Globally disable the cmd + tab switch

I would like to disable the default application switch, which is activated using the command line, to replace it with my own.

I saw in this answer that I can use such a call to disconnect the switch:

    OSStatus status = SetSystemUIMode (kUIModeContentSuppressed,
                                   kUIOptionDisableProcessSwitch);

But this only works when my application is active front most applications, which, of course, will not. So, is there any other way to capture these keystrokes or is there a way to keep my application active, but still transmit keystrokes (possibly with a full-screen transparent window)?