... versuchs mal damit.

Dim workspace As New NotesUIWorkspace
Dim uidoc As NotesUIDocument
Set uidoc = workspace.CurrentDocument
If uidoc.FieldGetText("Index")="" Then
Msgbox "Bitte geben Sie eine Kategorie ein!",16,"Hinweis!"
Exit Sub
End If
Call source.FieldSetText ( "status", "XX?" )
Call uidoc.Refresh