Well there is no way to know because we don't know how it works. If it simulates a 1 key USB keyboard, and then the BIOS is set to wakeup on USB and the specified keyboard stroke, then yes it will work. If it is some proprietary mac thing, then no. I am not a big mac user, so I am not really up to speed with their hardware or technologies.
If you want it to power on without opening it, do essentially the same thing. Get a cheap keyboard, hack it apart to get at the circuit board, and wire 2 connects onto it. These connects depending on where you will connect will be a button press. Then in the BIOS set it to wake on keyboard cammands and map it to that key. Easiest way to tell what key it is, would be to open notepad or word or something and push it! See what it does. That should eliminate over half the possibilities of a 108key keyboard.
Another option is LAN booting. There is a thread somewhere on that. I am by no means on expert on this, but I believe it sends out the "special key" multiple times in quick succession along with the IP or something and that is the magic codeword to power on. Of course this means that your NIC would have to be constantly on, but you said you have a laptop so an internal battery should be fine for holding it in standby. I get 152 hours in standby according to my little monitor thingy on my laptop, so that is plenty even if you go on a small vacation. Worst that could happen would be you would have to open the lid and push the button!