I made a plug-in for 3dsMax that creates a Newton tree collision from your model and then serializes it to a file.
You can download it (and the source) here.
It should work with 3dmax 6 and later.
The source is a VS2003 project, because I just couldn't get it to compile with VS2005 express.
Installation and other information is in the readme file. If you're having problems compiling it, I doubt I can help because I'm new to making plugins for 3d max.
It's nothing special but I hope it will be useful for someone.
Edit: Updated the link, as requested.
If you get a "403 Forbidden", just copy and paste the link to your address bar.