Casting hexadecimal IPs to readable content

Dear Friends,

My PhpBB forum with 4000 users was hacked in Switzerland.

Enquirers (not my own idea) proposed that I look for certain IPs in my
PostgreSQL 8.2 database. The problem is that PhpBB stored IPs as
strings, which seem to be more or less encoded.

In PhpBB, IPs are stored as Hexa:
"54dc0636"
"52e1fcb6"

How to cast these values to readable content?
Any idea ? This is an important issue for me.
Thank you for any help.

Kind regards,
Jean-Michel