I want to start using an external monitor with my Macbook, most likely exclusively when i'm in my room.

The problem is that i have an annoying cat in the appartment and, at least back when i had my PC, he'd occasionally wake my computer up by stepping on the keyboard/moving the mouse.

I fixed the problem by making it so that i could only wake/power on my PC my pressing CTRL+ESC (the cat's not smart enough to wake it then ).

My question is, is it possible to do the same thing on a Macbook? I know that when the macbook is sleeping, with an external monitor plugged in, just moving the mouse or using the keyboard will wake it. Can this be limited to a specific key sequence?