It's almost deff possible..
If it's .asc.. It's really easy
Just goto the Open menu in O2Light, and in the file type box, find the *.asc one
Find your file, and open it..
Tada
Look for a gun tutorial for the rest
If not.. Try LithUnwrap (Look for my Halflife > OFP tutorial thread, at the bottom of the 3d modeling forum bit)
If that can open it, save it as a asc file, and open it.
If not, use Global Ops modeling tools (If there is any.. if not, your in trouble), to export the models to something Lithunwrap can open (Quite a lot)
If you can confirm the file extension, I can help a lot more
- Ben