Do any of you know how to write AR codes for 3rd gen?

I need a code that will enable the national dex in Emerald. I HAVE BEEN ALL OVER GOOGLE looking for this code and all I can find is a GameShark version of the code that is in the wrong format to work correctly with my GBA AR Max Duo. I just want to play Emerald with my Singing Meowth from XD Gale of Darkness but I can't with the stupid National Dex restriction in place, so if anyone can help I will literally e-suck your dick.