Sub Zoom()
Dim coef
coef = 2 'à adapter
With ActiveSheet.Shapes(Application.Caller)
.LockAspectRatio = True
If Right(.Name, 2) = "_Z" Then
.Width = .Width / coef
.Name = Left(.Name, Len(.Name) - 2)
Else
.Width = .Width * coef
.Name = .Name & "_Z"
.ZOrder 0 'place en 1ère position
End If
End With
End Sub