Here's what I mean.
It has some demo files in it. I'll use the head.
You create a sculpture in Sculptris, then save it as an .OBJ file.
This is one I just made, playing around the second time.
Then open your 3d CAM, like Mesh CAM, VcarvePro, etc..
Open a new job, and then import a 3D model (The .obj file you made).
Set it in the material block, where you like it, and OK it.
Finish by smoothing the triangles, and any last minute tweaking.
Then run the toolpaths.
It should look something like this, when you're done
Actually this video shows it a lot better. Making a base relief in ZBrush: