Trouver une valeur dans un autre classeur

Sub rrecherche()
Dim MaRecherche As Integer
Dim Ws As Worksheet
Dim C As Range
Dim FirstAddress As String
Dim Message As String

 Workbooks("Calendrier.xls").Activate
   With Workbooks("Calendrier.xls")
      MaRecherche = 4419  ' comme la viande, c'est à varier
      Message = "La valeur " & MaRecherche & " a été trouvée :" & Chr(10)
      For Each Ws In .Worksheets
         With Ws
            Set C = .Columns("A:Z").Find(What:=MaRecherche, LookIn:=xlValues, LookAt:=xlPart)
            If Not C Is Nothing Then
               FirstAddress = C.Address
               Do
               Message = Message & "- dans la feuille " & Ws.Name & ", cellule " & C.Address & Chr(10)
               Set C = .Columns("A:Z").FindNext(C)
               Loop While Not C Is Nothing And C.Address <> FirstAddress
            End If
         End With
      Next Ws
      MsgBox Message
   End With
End Sub

Set cellu = Range(num & ligne : num & 200).Find(k, lookat:=xlWhole)

Set cellu = Range("BQ45" : "BQ200").Find(k, lookat:=xlWhole)

Set cellu = Range(num & ligne & ":" & num & "200").Find(k, lookat:=xlWhole)