Need to create custom aphanumeric naming for custom doctype

I have custom doctype “Class”
need to name it with two letter suffix following the sequence like
00,01,02,…0A,0B,…0Z,10,11,12,…1Z,…,A0,A1,…ZZ
How do i achieve this?
any ideas ?

Are you talking about the naming series? If yes, just open the doctype via Doctype List and modify the naming:

image

So you could write: PRE.##### and the system will automatically change the ‘#####’ by numbers → PRE.00001, PRE.00002, …

Thanks for the reply but the series is only capable of incrementing number , I need
Alphabets too.