Copy the contents of src-common and src-main from your authorized copy of Cobalt Strike into the src-common and src-main directories.
You'll need to modify patch.c to read (char *)buffer instead of buffer. VS will tell you which lines are broken when you try to compile. :)
In Visual Studio, go to Build -> Batch Build and click "Select All." There should be 20 in total.
You should see ========== Build: 20 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========
You'll find the compiled output in the "output" directory.
Copy your "artifact.cna" into that directory
If things like this interest you, I'm hiring senior-level Red Teamers. HMU.