How to import OBJ to IMD Editor ?

[Goblin Wizard]

I've finally managed to do this but new new problem appeared. After importing model from 3DSMax it contains no spheres (for collision detection) so it's indestructible. Even OBJ file exported from IMD doesn't contain this information too.
Generally the question is: How to add these spheres?
If we can't do this importing new models is really pointless.