I am in Law Enf and our computer system is set up to require new, never
before used, passwords for every user every 90 days.

I have been attempting to generate random passwords in excel using this:
=CHAR(RANDBETWEEN(48,122))
It works fine except that it also creates passwords with characters other
than numbers and upper/lower case letters.

Can someone tell me how to generate random passwords resulting in only the
characters mentioned?

Thanks in advance... Russ