Hi there,
I haven't a clue
what those keycodes you mention are for; however, it will definitely help others answer your question if you provide some basic details with your question, most importantly: Which Linux are you using, what type of PC, that kind of thing.
NOW.. On most Linuxes that I am remotely familiar with, there is a file on the system called 'inittab' and it is *usually* located in the /etc folder.
In this file, you can configure what action you wish to happen when the system detects the CTRL-ALT-DELETE sequence (yep, this combination is built-in).
You can read about the syntax of the 'inittab' file using the man pages (type 'man inittab' in a console) though there should already be a configuration in the file which maybe you can just change to make your machine shut down instead of whatever it does now.
If you happen to be using a Linux which does NOT already have an inittab file, please post what Linux it is (Name, version, etc.) and hopefully someone more versed in that particular variety can assist you more.
I hope this helps get you on the right track; if you need further help, please just ask!
Sasha