How to change SAP Logon language using VBA code to update it directly in Registry Editor

I am trying to rework a code from another topic (HERE) and the answer from user Storax to suit my current needs. However, in the quoted example the values are in Boolean type (1 and 0) while in my case they should be String (i.e. text).

I would like to create a simple code where:

to reach the path Computer\HKEY_CURRENT_USER\SOFTWARE\SAP\General (from the Registry Editor/regedit.exe), to read and to store the initial value of the file "Language" REG_SZ as a constant (e.g. DE - German language*) in Sub_1;
to change the value from the initial constant to the variable EN (i.e. English) in Sub_2;
to revert back the change to the original/initial state (i.e. DE or the variable to become equal to the constant) in Sub_3.

*Remark: The initial value of the language can be different than DE, e.g. ES, FR, etc. or even EN.

Why? Because in another sub routine, I would like to call (in its very beginning) Sub_1 and Sub_2, then the steps of the main routine to follow as usual, and finally (at the very end) to call Sub_3 which to restore the remembered value of the language (i.e. the constant stored in Sub_1).

Or with other words, I would like to set SAP Logon language to be English (no matter which other language is chosen currently) in order to execute some steps in SAP for data extraction and when it is done, to reset the SAP Logon language back to its initial value.

Class Module clsRegistry2

Option Explicit

Function ReadRegKey(RegKey As String) As Variant
Dim wsh As Object
    Set wsh = CreateObject("WScript.Shell")
    On Error GoTo NoRegkey
    ReadRegKey = wsh.regread(RegKey)
    Set wsh = Nothing
    Exit Function
NoRegkey:
    ReadRegKey = ""
End Function

Function DeleteRegKey(RegKey As String) As Boolean
Dim wsh As Object
   Set wsh = CreateObject("WScript.Shell")
   On Error GoTo NoRegkey
   wsh.RegDelete RegKey
   DeleteRegKey = True
   Set wsh = Nothing
   Exit Function
NoRegkey:
    DeleteRegKey = False
End Function


Function WriteRegKey(RegName As String, RegValue As Variant, RegType As String) As Boolean
Dim wsh As Object
   Set wsh = CreateObject("WScript.Shell")
   On Error GoTo NoRegkey
   wsh.RegWrite RegName, RegValue, RegType
   WriteRegKey = True
   Set wsh = Nothing
   Exit Function
NoRegkey:
    WriteRegKey = False
End Function

Class Module clsSapgui2

Option Explicit
Const mRegNameBase2 = "HKEY_CURRENT_USER\Software\SAP\General\"
Const mLanguage = "Language"

Dim mRegKey As New clsRegistry

Property Get Language() As String
    UserScripting = ReadRegKey(mLanguage)
End Property

Property Let Language(newVal As String)
    WriteRegKey mLanguage, CBoolToVal(newVal)
End Property

Private Function CBoolToVal(bVal As Boolean) As Byte
    If bVal Then
        CBoolToVal = 1
    Else
        CBoolToVal = 0
    End If
End Function

Private Function ReadRegKey(sRegValue As String) As String
    Dim sRegName As String
On Error GoTo NoRegkey
    sRegName = mRegNameBase2 & sRegValue
    ReadRegKey = mRegKey.ReadRegKey(sRegName)
    Exit Function
NoRegkey:
    ReadRegKey = 0
End Function

Private Function WriteRegKey(sRegKey As String, ByVal sRegValue As String) As Boolean
    Dim sRegName As String
On Error GoTo NoRegkey
    sRegName = mRegNameBase2 & sRegKey
    WriteRegKey = mRegKey.WriteRegKey(sRegName, sRegValue, "REG_SZ")
    Exit Function
NoRegkey:
    WriteRegKey = "EN"
End Function

Module Z_SAP_Options

Sub Sub_2 ()
    Dim mySapGui2 As New clsSapgui2

    With mySapGui2
        .Language = "EN"
    End With

End Sub

When I run the sub routine, I receive the following error message "Compile error: ByRef argument type mismatch", highlighting (newVal).

Property Let Language(newVal As String)
    WriteRegKey mLanguage, CBoolToVal(newVal)
End Property

Again, this is the preexisting code which I tried to adapt. I believe the type should be changed from Boolean to String (or other). I couldn't write Sub_1 and Sub_3 so far. Apologies from my side. The VBA coding for Registry Editor is brand new territory for me.

I would appreciate highly if it is possible someone to assist me in resolving the case of mine.

Solution

Take a look at the extended version of the class below. However, I am not certain if this will be of much help to you. The key point is that you always need to completely restart SAPGUI for the changes to the registry to take effect. This means you must close every session and restart SAPLOGON

You can test it with the following code

Sub testit()
    Dim myGuiReg As New GuiReg
    
    Debug.Print myGuiReg.Language
    
    Dim savedUserLang As String
    savedUserLang = myGuiReg.Language
    
    myGuiReg.Language = "EN"
    
    ' do whatever is needed
    ' ATTENTION
    ' Restart of SAPGUI is neccessary otherwise
    ' changes do not have any effect
    
    
    myGuiReg.Language = savedUserLang
    
    
End Sub

Classes needed (Sorry, I renamed them)

Class GuiReg

Option Explicit

' Enumeration for SecurityLevel
Enum guiLevel
    Disabled = 0
    Customized = 1
    StrictDeny = 2
End Enum

' Enumeration for DefaultAction
Enum guiAction
    Allow = 0
    Ask = 1
    Deny = 2
End Enum

' Only certain combinations with SecurtiyLevel are allowed resp. reasonable
' SecurityLevel DefaultAction
' 0 0 , 1 0, 1 1, 1 2, 2 2

Const mRegNameSecurity = "HKEY_CURRENT_USER\Software\SAP\SAPGUI Front\SAP Frontend Server\Security\"
Const mUserScripting = "UserScripting"
Const mWarnOnAttach = "WarnOnAttach"
Const mWarnOnConnection = "WarnOnConnection"

' 0 = Deactivated, 1 = Allow , 2 = rule based
Const mSecurityLevel = "SecurityLevel"
' Deafult Action
Const mDefaultAction = "DefaultAction"

Const mRegNameScripting = "HKEY_CURRENT_USER\Software\SAP\SAPGUI Front\SAP Frontend Server\Scripting\"
Const mShowNativeWinDlgs = "ShowNativeWinDlgs"

Const mRegNameLang = "HKEY_CURRENT_USER\Software\SAP\General\"
Const mLang = "Language"

Dim mRegKey As Registry

Property Get DefaultAction() As Byte
    DefaultAction = ReadKey(mRegNameSecurity, mDefaultAction)
End Property

Property Let DefaultAction(nVal As Byte)
    WriteKey mRegNameSecurity, mDefaultAction, nVal
End Property

Property Get ShowNativeWinDlgs() As Byte
    ShowNativeWinDlgs = ReadKey(mRegNameScripting, mShowNativeWinDlgs)
End Property

Property Let ShowNativeWinDlgs(newVal As Byte)
    WriteKey mRegNameScripting, mShowNativeWinDlgs, newVal
End Property

Property Get UserScripting() As Boolean
    UserScripting = ReadKey(mRegNameSecurity, mUserScripting)
End Property

Property Let UserScripting(newVal As Boolean)
    WriteKey mRegNameSecurity, mUserScripting, CBoolToVal(newVal)
End Property

Property Get WarnOnAttach() As Boolean
    WarnOnAttach = ReadKey(mRegNameSecurity, mWarnOnAttach)
End Property

Property Let WarnOnAttach(newVal As Boolean)
    WriteKey mRegNameSecurity, mWarnOnAttach, CBoolToVal(newVal)
End Property

Property Get WarnOnConnection() As Boolean
    WarnOnConnection = ReadKey(mRegNameSecurity, mWarnOnConnection)
End Property

Property Let WarnOnConnection(newVal As Boolean)
    WriteKey mRegNameSecurity, mWarnOnConnection, CBoolToVal(newVal)
End Property

Property Get SecurityLevel() As Byte
    SecurityLevel = ReadKey(mRegNameSecurity, mSecurityLevel)
End Property
 
Property Let SecurityLevel(ByVal newVal As Byte)
    WriteKey mRegNameSecurity, mSecurityLevel, newVal
End Property

Private Function CBoolToVal(bVal As Boolean) As Byte
    If bVal Then
        CBoolToVal = 1
    Else
        CBoolToVal = 0
    End If
End Function

Property Get Language() As String
    Language = ReadKey(mRegNameLang, mLang)
End Property

Property Let Language(nVal As String)
    WriteKey mRegNameLang, mLang, nVal, REG_SZ
End Property

Private Function ReadKey(regKey As String, regValue As String) As Variant

    Dim regName As String
    
    On Error GoTo EH

    regName = regKey & regValue
    ReadKey = mRegKey.ReadKey(regName)
    Exit Function

EH:
    ReadKey = ""

End Function

Private Function WriteKey(keyPath As String, key As String, ByVal newValue As String, Optional ByVal inpType As regType = REG_DWORD) As Boolean

    Dim regName As String

On Error GoTo EH

    regName = keyPath & key
    WriteKey = mRegKey.WriteKey(regName, newValue, inpType)
    Exit Function

EH:
    WriteKey = False

End Function

Function isGuiRunning()
    
    Dim sapAppl As Object
    
    On Error Resume Next
    Set sapAppl = GetObject("SAPGUI")
    On Error GoTo 0
    
    If sapAppl Is Nothing Then
        isGuiRunning = False
    Else
        isGuiRunning = True
    End If

End Function

Private Sub Class_Initialize()
    Set mRegKey = New Registry
End Sub

This is the class Registry (I renamed the class)

Option Explicit

Private wsh As Object

Enum regType
    REG_DWORD = 0
    REG_SZ = 1
    REG_EXPAND_SZ = 2
    REG_BINARY = 3
End Enum

Function ReadKey(key As String) As Variant

    On Error GoTo EH
        
    ReadKey = wsh.RegRead(key)
    Exit Function

EH:
    ReadKey = vbNullChar

End Function


Function DeleteKey(key As String) As Boolean

    On Error GoTo EH
    
    wsh.RegDelete key
    DeleteKey = True
    
    Exit Function
   
EH:
    DeleteKey = False

End Function

Function WriteKey(key As String, ByVal Value As Variant, Optional ByVal inpType As regType = REG_DWORD) As Boolean
    ' regType could be REG_SZ, REG_EXPAND_SZ, REG_DWORD, REG_BINARY
    
    On Error GoTo EH
   
    wsh.RegWrite key, Value, convRegType(inpType)
    WriteKey = True
   
    Exit Function
   
EH:
    WriteKey = False

End Function

Private Function convRegType(inpType As regType) As String

    Select Case inpType
    
        Case REG_BINARY
            convRegType = "REG_BINARY"
        
        Case REG_DWORD
            convRegType = "REG_DWORD"
        
        Case REG_EXPAND_SZ
            convRegType = "REG_EXPAND_SZ"
    
        Case REG_SZ
            convRegType = "REG_SZ"
        
        Case Else
            convRegType = ""
    End Select

End Function

Private Sub Class_Initialize()
    Set wsh = CreateObject("WScript.Shell")
End Sub