protection de colonnes

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count > 1 Then Exit Sub
Dim C As Range
On Error GoTo FinChange
Application.EnableEvents = False
If Target.Column >= 22 And Target.Column <= 26 And Target = "" Then Application.Undo
If (Target.Row - 10) Mod 41 < 4 Then
Set C = Cells(Target.Row, 5)
Do While C.Row < Target.Row + 41 ' Si 40 lignes par client
If C = MemoSel Then Exit Do
Set C = C(2, 1)
Loop
If Target = "" Then
If C = MemoSel Then
MemoVal = Target.Offset(C.Row - Target.Row, 0).Value
Target.Offset(C.Row - Target.Row, 0) = ""
BoolDépl = True
End If
Else
If C = MemoSel Then
If BoolDépl = True Then
Target.Offset(C.Row - Target.Row, 0) = MemoVal
BoolDépl = False
End If
End If
End If
End If
FinChange:
Application.EnableEvents = True
End Sub