Globally disable the cmd+tab app switcher

I'd like to be able to disable the default app switcher which is activated with command-tab to replace it with my own.

I've seen in this answer that I can use a call like this to disable the switcher:

    OSStatus status = SetSystemUIMode (kUIModeContentSuppressed,
                                   kUIOptionDisableProcessSwitch);

But this only works whilst my app is the active front most app, which of course it wont be. So is there another way to capture these keystrokes, or is there a way to keep my app active but still pass keystrokes through (maybe with a fullscreen transparent windo开发者_JAVA技巧w)?

You can't, and for good reason; it would be a vector for attack by a malicious coder.