Option Explicit
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
Dim mafeuille As String
If Target.Count > 1 Then Exit Sub
If Not Application.Intersect(Target, Sh.Range("B15:S70")) Is Nothing Then
mafeuille = IIf(Sh.Name = "Feuil1", "Feuil2", "Feuil1")
Application.EnableEvents = False
Sheets(mafeuille).Range(Target.Address).Value = Target.Value
Application.EnableEvents = True
End If
End Sub