Public Sub test()
Dim x, chemin As String, NomFichier As String, Extension As String
chemin = "C:\projet\200"
NomFichier = "tva"
Extension = ".xls"
x = "a"
chemin = chemin & x & "\"
NomFichier = NomFichier & x & Extension
MsgBox chemin & NomFichier
End Sub