Erreur 438 sur déclaration de plage de range

Dim nom As String, plage As Range
nom = ActiveWorkbook.Name
Set plage = Workbooks(nom).Worksheets("Feuil1").UsedRange

Sub Testing()
    parcoursColonnes ("A")
    
End Sub

Function parcoursColonnes(ByVal colonne As String)

    Dim plage As Range
    Dim cel As Range
    Dim n As Long
    i = 2
    
    numCol = Columns(colonne).Column
    'henry = Columns("A").cells.Count
    'bernard = Application.Sheets(1).UsedRange.Rows.Count
    nom = ActiveWorkbook.Name
    
    
    'Set plage = Application.Sheets(1).Range("C1:C12")
    
    Set plage = Application.Workbooks(nom).Worksheets("Feuil1").UsedRange.Columns("A").cells
    n = 0
     
    For Each cel In plage
        i = i + 1
        If (cells(i, numCol).Value <> "") Then
            n = n + 1
            cells(i, numCol).Value = ""
            ListeMOE (cells(i, numCol))
        End If
    Next
    parcoursColonnes = i
    
End Function

Function ListeMOE(ByVal cel As Range)
    listeval = "DSI, RES, DSI&RES, BULL, DSI&BULL, Diginext, Autre"
    cel.Select
    With Selection.Validation
        .Delete
        .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:=xlBetween, Formula1:=listeval

    End With
End Function