Comme ceci
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column = 11 And Target.Row > 2 And Target.Row < 15 Then
If Target <> "" And Target.Offset(0, -1) = "" Then
Cells(Target.Row, Target.Column - 1).Value = Cells(Target.Row, Target.Column + 1).Value
Cells(Target.Row, Target.Column + 1).ClearContents
End If
End If
End Sub