Function GetParentDocument( doc As NotesDocument )
  Dim db As NotesDatabase
  Dim parentDoc As NotesDocument
  Set db = doc.ParentDatabase
  If doc.IsResponse Then
    Set parentDoc = db.GetDocumentByUNID _
    ( doc.ParentDocumentUNID )
  End If
  Set GetParentDocument = parentDoc
End Function
This function can be called from any script. For example:
dim myQuestion as NotesDocument
dim yourAnswer as NotesDocument
'...set value of yourAnswer...
set myQuestion = GetParentDocument( yourAnswer )