ajouter des "0" devant des chiffres

Sub ZéroDevant()
Dim l&, n&, Cel As Range
    l = Val(InputBox("Longueur du code ?", , 4))
    If l > 1 Then
        For Each Cel In Selection.Cells
            With Cel
                If Not IsEmpty(.Value) Then
                    If IsNumeric(.Value) Then
                        If Len(CStr(.Value)) < l Then
                            .Value = "'" & Right$(String(l, "0") & CStr(.Value), l)
                            n = n + 1
                        ElseIf Len(CStr(.Value)) = l Then
                            .Value = "'" & CStr(.Value)
                        End If
                    End If
                End If
            End With
        Next
    End If
    MsgBox IIf(n, n, "Aucun") & " code" & IIf(n > 1, "s", "") & " modifié" & IIf(n > 1, "s", "") & "."
End Sub

="Code "&TEXTE(A1;"0000")

="Code "&A1