Option Explicit
Private Sub Workbook_Open()
Dim T_Date, Msg As String, Cel As Range
T_Date = Date
For Each Cel In Feuil1.Range("D3:D12")
If T_Date >= Cel.Value Then
Msg = "Attention, il y a des dates à échéance de VGP dépassées"
Exit For
End If
Next
If Msg <> "" Then MsgBox Msg
End Sub