Bonjour
Code à placer dans le module de la feuille (clic droit sur l'onglet de la feuille ---> Visualiser le code)
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count > 1 Then Exit Sub
If Not Intersect(Columns("A"), Target) Is Nothing Then
If Target <> "" Then
Range("I" & Target.Row).Borders(xlDiagonalUp).Weight = xlThin
Range("I" & Target.Row).Borders(xlDiagonalDown).Weight = xlThin
Else
Range("I" & Target.Row).Borders(xlDiagonalUp).LineStyle = xlNone
Range("I" & Target.Row).Borders(xlDiagonalDown).LineStyle = xlNone
End If
End If
End Sub