Hi Philipp,
Is the user ID same as the windows login ID? If yes, then probably you can modify the code to:
Sub Button1_Click()
Dim MyName as string
Dim MyPW as string
MyName =fOSUserName()
MyPW = InputBox("Please enter password", "Password")
client.Connect "BIS PROD", MyName, MyPW
client.OpenSpecificDocument "spreadsheetABC.xlsm", "", "", "Input Schedules", ""
End Sub
Function fOSUserName() As String
Dim lngLen As Long, lngX As Long
Dim strUserName As String
strUserName = String$(254, 0)
lngLen = 255
lngX = apiGetUserName(strUserName, lngLen - 1)
If lngX <> 0 Then
fOSUserName = Left$(strUserName, lngLen - 1)
Else
fOSUserName = ""
End If
End Function
Hope this helps.