I'm not sure if there are any tools to do that. I do know that you can get the
Accessory Converter from Haptek that converts 3dsMax objects into HTR's. They also do another tool called the
DeltaSetMaker that converts OBJ files into HTR's.
As far as I know those are the only options - so I'd get in touch with Haptek and ask what the prices are nowerdays.
To get some more info on those products go to
www.haptek.com and look in their 'Developers' section, then from there choose 'Commercial Licensing'.