VBA Undo ? oder zwischenspeichern? oder direkt?

Private Sub Worksheet_Change(ByVal Target As Range)
Dim strCom As String
Dim strCom2 As String
Dim myCom As Object
On Error GoTo ErrorHandler
Application.ScreenUpdating = False
Application.EnableEvents = False
ActiveSheet.Unprotect "matze"
'Teil1
If Not Intersect(Target, Range("H10:I40")) Is Nothing Then
If Target  "" Then
Cells(Target.Row, 3).ClearContents
Cells(Target.Row, 4).ClearContents
Cells(Target.Row, 5).ClearContents
Cells(Target.Row, 6).ClearContents
Cells(Target.Row, 7).ClearContents
Cells(Target.Row, 10).ClearContents
End If
End If
'Teil2
If Not Intersect(Target, Range("J10:J40")) Is Nothing Then 'entnahme Mehrarbeit
If Target  "" And Cells(Target.Row, 4).Value  "" And Cells(Target.Row, 6).Value = "" _
_
Then
Rows(Target.Row).ClearComments          'Kommentare der ganzen Zeile löschen
strCom = Cells(Target.Row, 4).Text
strCom2 = Cells(Target.Row, 10).Text
Set myCom = ActiveSheet.Cells(Target.Row, 4).AddComment 'Kommentar setzen
With myCom                      'Eingabe in Kommentar
.Visible = False
.Text Text:="von Arbeitsende " & strCom & "Uhr wurden " & strCom2 & "  _
Mehrarbeitsstunden abgezogen"
.Shape.Height = 30
.Shape.Width = 180
End With
Cells(Target.Row, 4).Value = Cells(Target.Row, 4).Value - Cells(Target.Row, 10). _
Value 'Spalte D
End If
If Target  "" And Cells(Target.Row, 6).Value  "" Then
Rows(Target.Row).ClearComments          'Kommentare der ganzen Zeile löschen
strCom = Cells(Target.Row, 6).Text
strCom2 = Cells(Target.Row, 10).Text
Set myCom = ActiveSheet.Cells(Target.Row, 6).AddComment
With myCom
.Visible = False
.Text Text:="von Arbeitsende " & strCom & "Uhr wurden " & strCom2 & "  _
Mehrarbeitsstunden abgezogen"
.Shape.Height = 30
.Shape.Width = 180
End With
Cells(Target.Row, 6).Value = Cells(Target.Row, 6).Value - Cells(Target.Row, 10). _
_
Value
End If
End If
ErrorHandler:
Application.EnableEvents = True
Application.ScreenUpdating = True
End Sub