I need to make a macro/ add-in that can:

1) Import a scanned STL file into SolidWorks and make it into a SolidWorks part file, where edits to the part can be made.

2) Use SolidWorks CAM to instantiate 3 axis milling machine, along with tool cribs and perhaps store/save a defined machine for future use. Then define the stock and the coordinate system. 

3) Use SolidWorks CAM to generate an operation plan for the part that was imported to be machined.

4) Optionally, produce GM codes for export.

Basically, the purpose of the software would be to streamline the process between importing a STL file and producing an operation plan to generate that part.

I'd like to know which way to go about doing this task. Is it easier to program a macro using VBA that can do this, along with storing the data and displaying forms, or do I need to program an add-in using C# for this?

I'm very confused about learning to use the SolidWorks CAM API as there seems to not be much (or any ) useful resources online that can guide me in getting SolidWorks CAM to do the things mentioned above.

Any help guiding me will be appreciated, please ask me for any clarifications.