How can I Generate an alpha-numeric Unique ID in MS Access

How can I automatically assign each record with a unique alphanumeric identifier (e.g. AWAZ0001) when a record is first created. The first 4 alpha characters are pre-defined in a field of their own and ideally, the 4-digit numeric part is a date identifier as to when the record was created.

I would appreciate any suggestions as to how to go about accomplishing this. I would also settle for some alternative in automatically assigning some kind of unique alphanumeric identifier.