really basic question- scaling 3D shape?

I have a question that is probably quite basic to anyone who has CNC experience: if I have a program for a three-dimensional shape (say, a Volkswagen Bug), can I mill out a large model a foot long and a small one an inch long?

I'm interested in creating some models for an N-scale model railroad. At 1:160th scale, details are easier to check if I create a larger protype first. Also I may want to make the same model in 1/87th scale.

So, can 'average' hobby-grade CNC software scale a complex shape up or down?

Thank you.

Depending on the format, you should be able to scale it in either a CAD or CAM program.

Thank you.

With just the CNC code, it will be more difficult. If you have the source 3D model, and created the code in CAM, then it is pretty easy.

Oops, I guess I misread that. If all you have is the g-code, it is possible to scale it with a control like Mach3, but you won't get as good of a result as if you scale it in CAD or CAM.