I'm busy with other things, maybe tomorrow I post the hack, but for now I'll post a D3D chams in color red.
How does it work?
The enemy will be behind the walls in red, and in your front (without walls) it will be normal!
How to use?
Only replace the folder Rez, which is usually in: C:\Program Files (x86)\Z8Games\CrossFire\rez
In particular I would like to thank @Rez modding NL, for providing me the necessary tools for editing via rez.
Crédits: Rez modding NL - BACKD00R