Option Explicit
Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
Dim St As String, Lien As String
If Target.Value = "" Then Exit Sub
If Not IsNumeric(Target.Value) Then
St = CStr(Target.Value)
Else
St = Target.Address
St = Range(Chr(Asc(Mid(St, 2, 1)) - 1) & Mid(St, 3, Len(St)))
End If
Lien = "http://fr.wikipedia.org/wiki/" & St
ActiveWorkbook.FollowHyperlink Address:=Lien, NewWindow:=True
End Sub