WoL over a airport router

I often need to be able to access my computer remotely when I am away
form home, but I also do not want to keep it awake all of the time.
So, I decided to try the WoL (wake-on-lan) method of waking my
computer up when I am gone. Obviously my attempts have so far, hence
this Post.

my set-up:

cable modem > apple's airport Extreme base station > ethernet
LAN to PowerMac G5

I am not sure whether apple includes a WOL compatible ethernet card.
Although I think that they do. Now, If I send the WoL magic packet
to my computer from outside of the network shouldn't it wake my
computer? Do I have to set the airport base station to forward
something?

Sorry I can't include anymore info, but I am lost as it is.

I would really appreciate it if anyone could give me some help in this
situation.