Userform/Masque de saisie textbox ,format 0000/00

Option Explicit
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
 Dim pos As Integer
 Dim caract, rep As String
On Error Resume Next 'permet de travailler sur la feuille
rep = Target.Value 'valeur de la cellule
If rep = "" Then Exit Sub 'si cellule vide
pos = InStr(rep, "/") 'position du /
If pos = 2 Then
caract = Left(rep, 1) 'on récupère le 1er caractère
rep = Replace(rep, caract, "000" & caract) 'on ajoute 000 au 1er carctère
Target.Value = rep 'on actualise la cellule
ElseIf pos = 3 Then
caract = Left(rep, 2)
rep = Replace(rep, caract, "00" & caract)
Target.Value = rep
ElseIf pos = 4 Then
caract = Left(rep, 3)
rep = Replace(rep, caract, "0" & caract)
Target.Value = rep
End If
End Sub

Private Sub TextBox1_Change()
If Right(TextBox1, 1) = "/" Then
TextBox1 = Format(Left(TextBox1, Len(TextBox1) - 1), "0000") & "/"
End If
End Sub