Rounding a back of a guitar neck

This would be a very hard shape to model in Carbide Create Pro as of v8.

Is modeling in a 3D CAD program such as:

and then importing as an STL (or using a 3D CAM tool such as Workshop/MeshCAM) an option?

The most likely option would be something like to:

If you have difficulties with this, upload a .c2d file with dimensions and profiles and we can walk through this with you.