Just a simple function to get the week number from a date.
Function GetWeekNr(InputDate As Long) As String
Dim intWeekday As Integer, intYear As Integer, lngDateSerial As Long, intWeeks As Integer
Dim strWeekNr As String
On Error GoTo ErrFunction
GetWeekNr = "0"
conv = 0
strWeekNr = ""
If InputDate < 1 Then Exit Function
intWeekday = Weekday(InputDate, vbSunday)
intYear = Year(InputDate + ((8 - intWeekday) Mod 7) - 3)
lngDateSerial = DateSerial(intYear, 1, 1)
intWeeks = (Weekday(lngDateSerial, vbSunday) + 1) Mod 7
conv = Int((InputDate - lngDateSerial - 3 + intWeeks) / 7) + 1
strWeekNr = Format(CStr(conv), "00")
ExitFunction:
GetWeekNr = strWeekNr
Exit Function
ErrFunction:
strWeekNr = "0"
GoTo ExitFunction
End Function