Railworks America

Just wondering, I have lots of routes for MSTS (NEC, Marias Pass, P42DC Genesis) and am wondering if it is possible to transfer stuff from MSTS to Railworks. (The search function has not turned up anything)

The short answer is no.

The long answer is:
some people have transfered some models. It is a long and painstaking process that doesn't save you a lot of effort.
You end up with a naked model that you have to unwrap, retexture, bake, etc. This model is usually of lower quality than one you would do from scratch.
Then you need to add lighting, snow textures, make the blueprints. That's it for scenery items.
Then for rolling stock you still need the physics, couplings, sounds, etc. More blueprints.
Then for engines you still don't have a cab, so you have to model and texture one and somehow make it fit your engine model. That usually takes longer than the engine model itself.
Then you have to do all of the physics and controls from scratch. Lots more blueprints.

As Chacal pointed out, there's a lot more involved than simply converting the shape. Far easier and shorter periods are spent starting from scratch. Besides which, MSTS models are old-generation and generally a bit clunky in as far as detail.