PROBOARD HOWTO-06
Searching the userbase index by name or alias.

The userbase index file, USERSIDX.BBS consists of records that contain the
32-bit CRC of the user name and alias. To search for the record number,
compute the CRC, then find the one entry that matches it. The number of
this entry in the file is the number of the user record in USERS.BBS and
USERSPB.BBS.

Note that Philippe's (or maybe RA author's) implementation of the CRC
calculation is buggy. First, make sure you upper-case the name (or the
alias) that you will be looking for. This makes sense. Next, compute the
CRC using the standard ANSI X3.66 method and polynomial and then, instead
of returning (~crc), return the plain (crc) as this is what's stored in
the file.

Check out the code in PB-Lib for a way to do this.
