The manual drawing part with the mouse is just a way to test out different paths of various shapes quickly and to test concepts. It would be possible to randomly generate a path once you decide on basic parameters of what you want, or save a path after you have drawn it and add that to your game... (the path is just a series of points - most of the paths I was trying were about a dozen or two points.)
MadSpy is doing a great job on what you are specifically after, I have seen quite a few people asking about how to make an object follow a path, and wanted to play around with a more general solution to the problem. So I had a bunch of concepts rattling around in my head - like could the path adapt itself to avoid obstacles, apply physics to the object so that it accelerates downhill and slows down going uphill, etc... Its a fun exercise to experiment on! C2 never ceases to amaze me. : )