Maybe you can get someone to convert it for you?  Don't we have a C4D forum here?

Or maybe you can contact the creator at Turbo Squid and ask if they can convert it to an .obj for you.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi