[EXCEL]-Convertir un numéro de semain en mois

Sub Sem_Jour()
Dim Sem As Integer
Dim Jour As Integer
Dim Mois As Integer
Dim D As Long, F As Long
Dim W As Integer
Dim TB
    Sem = 22 'exemple du N° de semaine
    
    TB = Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
    D = DateSerial(Year(Now), 1, 1)
    F = DateSerial(Year(Now), 12, 31)
    TB(1) = TB(1) + ((F - D) - 365)
    W = Weekday(D, vbMonday) 'Lundi=jour 1 de semaine
    Jour = ((Sem - 1) * 7)
    If W < 5 Then Jour = Jour + W - 1
    For Mois = 0 To 11
        W = W + TB(Mois)
        If W > Jour Then Exit For
    Next Mois
    Mois = Mois + 1
    
End Sub

Public Function SEM_MOIS(Sem As Range) As Integer
Dim NbJours As Integer, D As Long
    Application.Volatile
    If Sem < 1 Or Sem > 52 Then
        SEM_MOIS = "#ERREUR"
        Exit Function
    End If
    D = Weekday("01/01/" & Year(Now), vbUseSystemDayOfWeek)
    NbJours = ((Sem - 1) * 7) - D + 1
    D = DateValue("01/01/" & Year(Now)) + NbJours
    SEM_MOIS = Month(D)
End Function

    =SEM_MOIS(C23)