Avec VBA, pourquoi je n'arrive pas à insérer une image Web dans une cellule Excel ?

Sub GetShapeFromWeb(strShpUrl As String, rngTarget As Range)
   With rngTarget.Parent
      .Pictures.Insert strShpUrl
      .Shapes(.Shapes.Count).Left = rngTarget.Left
      .Shapes(.Shapes.Count).Top = rngTarget.Top
   End With
End Sub

Sub Test()
Dim WebImage$
WebImage = "http://www.stockvault.net/data/2011/04/05/121121/small.jpg"
Call GetShapeFromWeb(WebImage, Feuil1.[A1])
End Sub

ActiveSheet.Shapes.AddPicture _
"http://www.excel-downloads.com/forum/customavatars/avatar2115_15.gif", True, True, _
ActiveCell.Left, ActiveCell.Top, 70, 70