Assign customer to pricing group at registration by referrer code

[mcornell]

I have seaarched to no avail.
I need to have customer enter a referrer code at registration and use that code to assign to a customer group.

customer registers and enters referral code "myTest" and gets assigned to the wholesale group if an invalid referrer code entered defaults to retail group.

this is supposed to be for oscMax v2

Thanks in advance!