Sometimes IRC networks obfuscate hostnames to avoid users from getting
each others IP addresses. I need to be able to reverse engineer these
addresses.

An example is below:

Actual Host:
someone@ip192-168-0-1.florida.res.rr.com

IRC Obfuscated:
someone@24862c5a.24624475.res.rr.com

Anyone know how I can reverse engineer the first two sections of a
hostname on a network like this?

the first part is just the ip converted to hex

There's no way to decloak the hostnames without finding out the cloak
keys set in the ircd. If you want to get the ip, you could just dcc
chat with the person and check your outgoing connections (or use
$chan(NICK).ip if you're using mirc) to get the ip address.