@XG2003 : any particular reason you want to make something yourself, Grid Pie doesn’t come close enough?
Let me just guess: keyboard shortcuts. This is do-able, and should not be too hard to add, even for an inexperienced scripter.
Also: have you discovered that Grid Pie has a bigger brother (the Duplex port)? - check it out here.
It comes with live recording, and is basically more “integrated” into Renoise. No keyboard shortcuts though, Duplex is primarily aimed towards hardware controllers.