Sub Choix()
Dim chemin$, x$, n As Byte
chemin = ThisWorkbook.Path & "\" 'à adapter
Do
x = InputBox("Entrez 1, 2 ou 3 :", "Choix semaine", x)
If x = "" Then Exit Sub
n = Val(x)
Loop While IsError(Application.Match(n, [ROW(1:3)], 0))
[A2] = "='" & chemin & "[Rapport semaine " & n & ".xlsx]Feuil1'!A2" 'formule de liaison adaptable
End Sub