Public Sub test()
Dim folderPath As String
folderPath = [COLOR="Red"][I]le chemin de ton dossier[/I][/COLOR]
Dim myFso
Set myFso = CreateObject("Scripting.FileSystemObject")
'si le dossier n'existe pas, on quitte la macro
If Not myFso.FolderExists(folderPath) Then MsgBox "le dossier """ & folderPath & """ n'existe pas": Exit Sub
Dim myFold
'ouvrir le dossier
Set myFold = myFso.GetFolder(folderPath)
Application.ScreenUpdating = False
Dim curFile As File, curWbk As Workbook
'pour chaque fichier du dossier
For Each curFile In myFold.Files
'si l'extension est bien "xls"
If Split(curFile.Name, ".")(UBound(Split(curFile.Name, "."))) = "xls" Then
'on ouvre le classeur
Set curWbk = Application.Workbooks.Open(curFile.Path)
[B]'tu fais ton code ici (pour copier ta liste) ----------------------------------------------------[/B]
curWbk.Sheets("Liste").Range("A1").Value = "tototiti"
[B]'------------------------------------------------------------------------------------------------[/B]
'on ferme le classeur
curWbk.Close True
End If
Next curFile
Application.ScreenUpdating = True
End Sub