Select only if two character and two number

I looking for the function (or some other trick) to identify new input in the table, that will be a combination of two character and two number only. But I don't know how to recognize if these input that what I looking for. In that field user can input any values (ex. ‘ABCD' or ‘1234') but I want only first and second characters and third and fourth numbers (ex. ‘AB12').

Thanks in advance,
Alex Received on Sat Jun 29 2002 - 21:16:40 CDT