Alerte même infos dans colonne

Private Sub Worksheet_Change(ByVal Target As Range)
Dim i&, mes$, c As Range
If Target.Column > 2 And Target.Column < 255 And _
  Target.Row > 5 And Target(1) <> "" Then
  i = Application.Match(Target(1), Target(1).EntireColumn, 0)
  If i < Target.Row Then
    mes = Target(1).Address(0, 0) & " en doublon avec " _
      & Cells(i, Target.Column).Address(0, 0)
    Set c = Range("IU" & Rows.Count).End(xlUp)(2)
    If c.Row < 6 Then Set c = [IU6]
    c = Application.Proper(Format(Now, "dddd dd/mm/yyyy hh:mm:ss"))
    c(1, 2) = mes
    Columns("IU:IV").AutoFit 'ajustement largeur
    MsgBox mes, ,"Doublons"
  End If
End If
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
Dim c As Range, mes$
If Target.Column > 2 And Target.Column < 255 And _
  Target.Row > 5 And Target(1) <> "" Then
  Set c = Target(1).MergeArea.EntireColumn.Find(Target(1), Target(1), xlValues, xlWhole)
  If c.Row <> Target(1).Row Then
    mes = Target(1).Address(0, 0) & " en doublon avec " & c.Address(0, 0)
    Set c = Range("IU" & Rows.Count).End(xlUp)(2)
    If c.Row < 6 Then Set c = [IU6]
    c = Application.Proper(Format(Now, "dddd dd/mm/yyyy hh:mm:ss"))
    c(1, 2) = mes
    Columns("IU:IV").AutoFit 'ajustement largeur
    MsgBox mes, , "Doublons"
  End If
End If
End Sub