VB:
Private Sub Worksheet_Change(ByVal Target As Range)On Error Goto ws_exit:Application.EnableEvents = FalseIf Not Intersect(Target, Me.Range("C155")) Is Nothing ThenWith Target.Offset(30, 0).Value = .Offset(30, 0).Value + .ValueEnd WithEnd Ifws_exit:Application.EnableEvents = TrueEnd Sub