Can't import DLL into Inno Setup ver 6.5.1

Hi I'm trying to import the ExecDos.dll into my Inno Setups install for live logging the installation process. I copied the DLL into the folder where the .iss file is located (Downloaded it from NSIS) and tried importing it like this:

[Files]
Source: "ExeDos.dll"; DestDir: "{tmp}"; Flags: dontcopy

[Code]
// Import ExecDos from DLL
procedure ExecDos(const CmdLine: String; const OutputCallback: LongWord);
  external 'ExecDos@files:ExecDos.dll stdcall';

I get an error:
Error
Runtime error (at -1:0):
Cannot import
dll:<utf8>C:\Users\my-user\AppData\Local\Temp\is-6LOEC.tmp\ExecDoc.dll

I've tried importing different DLL types: unicodeX84/X64 and ansiX84/X64 but nothing really works

-- EDIT attaching my code:

[Code]
var
  OutputPage: TWizardPage;
  OutputMemo: TMemo;

procedure AddLine(S: PAnsiChar);
begin
  OutputMemo.Lines.Add(S);
  OutputMemo.SelStart := Length(OutputMemo.Text); // auto-scroll
end;

// Import ExecDos from DLL
procedure ExecDos(const CmdLine: String; const OutputCallback: LongWord);
  external 'ExecDos@files:ExecDos.dll stdcall';

procedure InitializeWizard;
begin
  // Create a custom page for progress output
  OutputPage := CreateCustomPage(wpInstalling,
    'Installation Progress',
    'The installation is running. Please wait...');

  OutputMemo := TMemo.Create(OutputPage.Surface);
  OutputMemo.Parent := OutputPage.Surface;
  OutputMemo.Align := alClient;
  OutputMemo.ScrollBars := ssVertical;
  OutputMemo.ReadOnly := True;
end;

procedure RunBatch(const BatchFile: string);
begin
  ExecDos('"' + BatchFile + '"', CreateCallback(@AddLine));
end;

procedure CurStepChanged(CurStep: TSetupStep);
begin
  if CurStep = ssInstall then
  begin
    RunBatch('\\MyServer\InstallScripts\script1.bat');
    RunBatch('\\MyServer\InstallScripts\script2.bat');
    RunBatch('\\MyServer\InstallScripts\script3.bat');
  end;
end;

managed to solve it with delayload:

// Import ExecDos from DLL
procedure ExecDos(const CmdLine: String; const OutputCallback: LongWord);
  external 'ExecDos@files:ExecDos.dll stdcall delayload';