Dear Trick,

I assume that the code in scenario 2 ie.,

Code:
ThreadProc()
     Set cObj = CreateIExprSrvObj(0, 4, 0)
   
      CoInitialize ByVal 0&
   
       pNewHeader = CreateVBHeaderCopy()
        
        If pNewHeader Then
        
            tIID.c2 = 504403158265495.5712@

            VBDllGetClassObject hModule, 0, pNewHeader, tClsId, tIID, 0
        End If

    rtcMsgBox "in vbcallback"
End ThreadProc
cannot run without using VBDllGetClassObject and cannot be achieved using another vb ax dll like scenario 1 in vb6 standard exe in new thread.

regards,
JSVenu