The system is quite easy to set up and if I was at home right now I'd throw something together for you, but alas not. So you'll have to do it yourself.
Oooh, how about a bit of pseudo-code to get me started :) Problem for me is setting up collision zones/borders using no 3D, just intricate mathematic formulas. Ahh who am I kidding, it's all way over my head :) But that's probably the one part I could never figure out by myself.
Thanks everyone for helping! I needed some fresh takes on this, yesterday my mind was completely blank.