Disable certain hotkeys in the editor?

So here is my problem: I am currently working on a small RTS game to expand my knowledge of the engine, and as is common in most RTS games that currently populate the market I am using the ctrl+(number key) keystroke to set control groups. The problem here is that, when using the game window, unity intercepts the keystroke and switches to a different window.

Now, I could go and just test using only the build and run option, but is there any way I can edit the hotkeys in the editor?

I am using unity free(for now) if that makes a difference.