Ie, try exporting to a program that has B3D features. For instance, MilkShape 3D. Export from Cinema4D to 3DSMax format then load that in Milkshape3D and export it to B3D format. It takes a little bit more time, but an extra 20 seconds compared to what it took to create the model, and bone it, and animate it? Thats nothing. :)
Firstly, the 3dsMax format is Max, and neither Milkshape nor Cinema4d support it. Secondly, if you mean 3ds, you apparently didn't read my earlier reply. 3ds DOES NOT SUPPORT BONE. It matters not a jot what loads them, they're not in there to be read. And finally, Milkshape's b3d exporter is missing a lot of key functions, so he'd lose half the information even if there was a way of getting it there.
I don't have C4d, so I can't say for sure, but if there's a directX 8 or later .x exporter, you can probably convert that .x to .b3d using Ultimate Unwrap without losing any information. Ultimate Unwrap is an excellent tool for conversion.
Caff makes a very good point though. Psionic modelled those soldiers in C4d, I think, so he must have a solution.