Private Sub Workbook_Open()
Dim ADExist As Boolean, AI As AddIn
ADExist = False
For Each AI In Application.AddIns
If AI.Name = "Mes fonctions" Then
ADExist = True
Exit For
End If
Next
If Not ADExist Then
Application.AddIns.Add "Z:\toto\Mes fonctions.xla", False
End If
If Not Application.AddIns("Mes fonctions").Installed Then
Application.AddIns("Mes fonctions").Installed = True
End If
End Sub