An anonymous developer has uploaded special files to PS3Dev Wiki, that will help with your Cex>Dex conversion, here is a quote from the readme:
A >>PS3D<< original:
libeeid (C) 2011-2012 ps3dev.net
If you can’t deliver the complete stuff, you should just keep your mouth shut
and not spread the EID0 algo out. This lib was meant to stay private because
we didn’t like the idea of every 1337 kiddo having a DEX console and annoying
developers with questions about running pirated games on it. Now we decided
to release it all into public although we won’t provide any support or do any
further work on it.
A lot of dedication, knowledge and time has gone into reversing ALL of the SPU
binaries to collect the informations in this library (that’s the fun part).
This is as far as you will get with firmware versions
Btw.: have fun reversing the SPU modules to find the required keys…
Special thanks to the people there: http://gitorious.ps3dev.net/+ps3dev-net