Cannot read Database or object read only

I am trying to query an Excel file from another file using VBA and ADO options. When I run this code it's throwing the error "Cannot updata, Database or object Read only":

Public Function fnExecuteXlQuery _
    (ByVal strPath As String,  _
    ByVal strQuery As String) As ADODB.Recordset

Dim rs As ADODB.Recordset
Dim conStr As String

On Error GoTo ErrorHandler

conStr = "Provider=Microsoft.Jet.OLEDB.4.0; " _ 
      & "Data Source=" & strPath & "; Extended Properties=Excel 8.0"

Set rs = New ADODB.Recordset
rs.Open strQuery, conStr, adOpenDynamic

Set fnExecuteXlQuery = rs

Exit Function
ErrorHandler:
Set fnExecuteXlQuery = Nothing
fnDisplayError Error(Err) & "Unable to fetch data from DTS...", ERROR_TYPE_ERROR
End Function

The "strPath" is the source Excel file and the "strquery" has the following SQL code:

Select [Activity],[Name],[Date],[Hours Spent] 
from [Time sheet$] 
where [Activity] = 'Billable Activities' 
Order by Name,date

Solution

Maybe all of what has been said in the comments just needs to be written out once more to make sure that you really got the solution right:

Option Explicit

Public Sub ConnectionToExcel()
Dim rstResult As ADODB.Recordset
Dim strConnectin As String
Dim strPath As String
Dim strSQL As String

strPath = "C:\Data\YourFile.xlsm"

strConnectin = "Provider=Microsoft.ACE.OLEDB.12.0;" & _
    "Data Source='" & strPath & "';Extended Properties=""Excel 12.0 XML;HDR=YES;IMEX=1"" "
Debug.Print strConnection

strSQL = "SELECT * FROM [Time sheet$] "

Set rstResult = New ADODB.Recordset
rstResult.Open strSQL, strConnectin, adOpenForwardOnly, adLockReadOnly, adCmdText

Sheet1.Range("A1").CopyFromRecordset rstResult

End Sub

Please note, that I am taking it one step at a time: (1) I am using a sub instead of a function. (2) The select has been simplified just to test the connection and can be later expanded upon. (3) Just writing back the result to the first sheet. (4) Further restricting the recordset to be adOpenForwardOnly only and adLockReadOnly.

Also, keep in mind that the above code uses early binding and thus requires you to set a reference to Microsoft ActiveX Data Objects 2.8 Library (or later) in Tools --> References....