Formulaire vba sur excel, liens entre cellules et checkbox à modifier

'Pour la liste déroulante Code client
Private Sub ComboBox1_Change()
    Dim Ligne As Long
    Dim I As Integer
    If Me.ComboBox1.ListIndex = -1 Then Exit Sub
    Ligne = Me.ComboBox1.ListIndex + 7
    ComboBox2 = Ws.Cells(Ligne, "B")
    For I = 1 To 7
        Me.Controls("TextBox" & I) = Ws.Cells(Ligne, I + 2)
    Next I
    CheckBox1.Value = Ws.Cells(Ligne, 10) = 1
    CheckBox2.Value = Ws.Cells(Ligne, 11) = 1
    CheckBox3.Value = Ws.Cells(Ligne, 12) = 1
End Sub

'Pour le bouton Modifier
Private Sub CommandButton2_Click()
    Dim Ligne As Long
    Dim I As Integer
    If MsgBox("Confirmez-vous la modification de ce contact ?", vbYesNo, "Demande de confirmation de modification") = vbYes Then
        If Me.ComboBox1.ListIndex = -1 Then Exit Sub
        Ligne = Me.ComboBox1.ListIndex + 7
        Ws.Cells(Ligne, "B") = ComboBox2
        For I = 1 To 7
            If Me.Controls("TextBox" & I).Visible = True Then
                Ws.Cells(Ligne, I + 2) = Me.Controls("TextBox" & I)
            End If
        Next I
        For I = 1 To 3
        Ws.Cells(Ligne, 9 + I) = ""
        If Me.Controls("Checkbox" & I).Value = True Then Ws.Cells(Ligne, 9 + I) = 1
        Next I
    End If
End Sub