If you want completely new maps I suggest someone creates a new landscape in 3ds format with a 3D program like 3DS Max. This new model/scene can be imported later to the 4ds format of HD2. I guess this would be easier than to try to put a new one together using parts from original maps.
Static objects like trees can be taken from HD2. For ground collision you can use an existing map. Collison of walls can be made with boxes or so.
If you keep it simple, with a small accessible area, it should be a nice start and not too difficult.
Nikita wrote: ...and i don't have enough skill for it
Its not so hard, there are lots of tutorials...
Dont know if any mission is made by french citizen but I guess you can find some made by someone who used english in scripting ( scripting commands are fixed, but "printf " and other descriptions behind "//" helps to understand scripts better. )
For example in my unfinished Brest mission, i used printf for almost everything in scripting.
First you take mission you want to use, delete all enemy with Revenged tool and then start building objectives...
Easy...isnt it ? hell no