I have the option of opening obj files under file>open in wildfire ( I havent looked in 2001).
In pro concept there is a filter for wavefront objects, I am assuming they are the same but I have never tried. I can try opening one for you if you like.
I just talked to a developer from PTC and he says you can open obj files in pro concept and that the obj extension is not specific to wavefront. So try the wavefront filter and