Extend Unity Player Settings?

I had been looking at http://unity3d.com/learn/tutorials/modules/intermediate/scripting/extension-methods and however through this method I have actually extended or added a player setting, I cannot see it in the GUI Window of Player settings and was wondering if I can actually extend the player settings gui window... not just the class? I was looking to add other key fields to the player settings before I would build my project to a platform. However I went over this a few days now, I am unable to figure this out, maybe a fresh mind can help?