Sub doublons()
Set LesDoublons = CreateObject("Scripting.Dictionary")
For Each cel In Range(Cells(1, 1), Cells(1, [IV1].End(xlToLeft).Column))
If Application.CountIf(Range("A1:IV1"), cel) > 1 Then
If Not LesDoublons.Exists(cel.Value) Then LesDoublons.Add cel.Value, cel.Value
End If
Next cel
For Each itm In LesDoublons.items
MsgBox itm & " : " & Application.CountIf(Range("A1:IV1"), itm) & " fois"
Next itm
End Sub