How do I create a custom Unique Identifier Number (UID) in Access Database?

I have a database that track all the final inspection lot and each lot# is a UID for that record. The problem I have is that I don't want the user entering the number manuly because they keep miss typing that created many problem. The format of my UID is like this: 63MYDDNN.

It must start with 63 then
the Month (A for January, B for Febuary ...)
then Y for Year (A for 2001, D for 2004 ...)
then DD for Today Date, and
NN for the sequence number of the entry. The NN can only go from 01 to 99.

I need to create a command buttom to pull the number follow this format and assigned it to the "Final Lot #" text box. This number is a UID and it Index. It can not be duplicated or blank. When the number have already assigned it can not be use again.

Can some please help.
Thank you
Vandat N.