Thanks for all your help. I've been reading this thread and the Pokedoc one, but I've got to keep asking some terribly newbie questions: since I will have to use the Pokedoc tool, do I still need an Action Replay? What for?
If I understood it right, the Pokedoc tool can make a backup of the HeartGold save file, store that save file on my computer and restore it to DS. Couldn't I just use PokeGen (it is safe, isn't it?) to edit it on my computer?
Sorry, but I still don't get the use of Action Replay. Maybe I am ignoring some part of the process. I am very newbie, please be patient.
If I need to read something else to understand the whole process, please help me. I feel like I am asking a lot of nonsense stuff. Sorry for that.