Yes, you have to load the obj you want into UVMapper, make the mapping the way you want it and resave the obj. Of course if you resave over the original, the new prop will have your mapping. If you want separate material zones, you'll have to set them up as such, which I think can only be done in the pro version. I haven't checked tho, so I may be wrong. It's been a long time since I've used the free verson :o).

Laurie