If I understand you then what you are saying is that you would like to create several key maps and allow each one to call the same copy of code underlying the mechanism for scanning pressed buttons/keys?
I need to think about this for a bit but the first thing that comes to mind is <> NO WAY!!! YOU CAN'T DO THAT!!! 
First off let me know if my assumption is right. I don't want to head down a rabbit hole just for the fun of it. But I'm already starting to get some ideas.