What your looking for is called the Collada script [ Angelica2 converter ]
This script is very very rare and only certain people have it, and will not be shared from what i know.
Even making the script is very hard, since you'll have to know what file does what.
Yes, models.pck contains a whole bunch of folders with models/animations and much more,
and theres a bunch of sites like RageZone that shares a whole lot of programs, or usefull things
wich helps you editing these files, unpacking .pck files and ofcourse the development of this game.
As Meg said, its alot of trail and error, but after some time you'll get more comfy with it,
and trying new things you havent, or find somehow scary to.
I wish you alot of luck!