Start Number at 000001 at new year.

[DeepTrouble]

I am generating a record number for each record with an expression as follows
Dim numZero As Integer
Dim strZero As String

numZero = 6 - Len(CStr(Me![Autonumber].Value))
strZero = String(numZero, "00001")

Me![Specimen Number].Value = CStr(Right(Year(DATE), 2)) + "-" + strZero + CStr(Me![Autonumber].Value)
This generates a new number for each specimen (we are a clinical lab). However, I would like to start Specimen number with 000001 on First Jan for each year, which is not the case at present.
Thanks a lot for your time and suggestion.