Can someone please help with this code?

We are currently using s2Member to sell memberships to our sports complex. s2Member essentially creates a WP user on a site after payment is received. We want our members to have a custom user ID, preferably one that can be automatically generated when the user account is created.

Ideally, this ID would be a 6 digit number, beginning with their state abbreviation.

For example, if a user from Maryland registers, they might get an ID like this: MD0006. Then, the next person from Maryland who registers would get the next number in the sequence, ie: MD0007.

I’m not against using a plugin for this, but I doubt one exists. We really need this functionality and we need it fast! I’m not too savvy on coding/hacking but I can find my way around if directed. Can anyone let me know what code I would have to use to accomplish this and where that code should go?

Thank you so much!