Private Sub CommandButton1_Click()
On Error GoTo Fin
Dim Cel_Ref As Range
Set Cel_Ref = Cells(Me.ListBox1.ListIndex + 3, Me.ListBox2.ListIndex + 2)
If Intersect(Cel_Ref, Range('C4')) Is Nothing And Intersect(Cel_Ref, Range('E5')) Is Nothing Then
Cel_Ref.Value = Me.TextBox1
Else
MsgBox 'Mise à jour interdite', vbOKOnly + vbInformation
End If
Fin:
End Sub