From Poser, choose File > Import > Wavefront OBJ

You will be prompted to locate the OBJ file you want to import. 

When the Import Objects dialog (shown above) appears, leave it at 100% Of Original Size, but UNCHECK all the other options (in other words, UNCHECK Centered and Make Polygon Normals Consistent. This will import the OBJ "as is".

The rest of the directions should be outlined in the LF1 to LF2 conversion thing. I don't have it, otherwise I'd comment further.