You can go into Carrrara with a .lwo file, however.  I can't remember off of the top of my head if you need Pro or not- but I would think that you would need to have the Pro version.   I did use a .lwo file in C6Pro for a render before and saved it as an .obj, but haven't tried in C8 yet. 

If you don't have Carrara, try downloading Blender.  I do believe you can open a .lwo file in there to work and save as an .obj file.  And, it's free.  If at all else fails- see if you can get a hold of a trial version of LW (read the download page first), if you can import the scene in a trial version and save it as an .obj-  there's the end of the problem.  You can uninstall LW after the trial's over or after you've finished and not have had to spend a dime or a massive amount of time looking for another way.