You can setup a routine which will "build" this number for you, although I
don't believe I'd store it in it's built form. I'm assuming that somewhere
you're storing the date your item is opened/built etc etc ... from here you
could get the month and year:
Dim strMonth As String
Dim strYear as String
strMonth = DatePart("m", YourDate) would give you the month
strYear = DatePart("yyyy",YourDate) would give you the year
As far as your sequence number, include a new column in your table named
lngSequence. To get the final part of your number, do this:
Dim lngMax As Long
lngMax = DMax("lngSequence","YourTable")
This would give you the largest value in that field. Add 1 to that number
and you've got your next sequence number (and this number would be stored in
you lngSequence field). So your displayed number would be:
strYear & strMonth & "-" & CStr(lngMax)