Option Explicit
Sub Renommer()
Dim chemin As String, fichier As String
Dim Fso As Object, newname As String, i&
Set Fso = CreateObject("Scripting.FileSystemObject")
chemin = "C:\Users\Rachid\Desktop\Fichiers_PDF\"
fichier = Dir(chemin & "*.*")
i = 1
Do While Len(fichier) > 0
i = i + 1
newname = Range("b" & i).Value
Fso.MoveFile fichier, chemin & newname
fichier = Dir()
Loop
End Sub