Are you talking about dolphin on your palm computer?
If you are then, let me tell you that the memcard for dolphin is already there, you just have to do what it tells you to do in the game. i.e. format the memcard but if you format it using a U.S game then you can only use the memory card for U.S games. If you format it with a Jap game the same happens. So if you have a Jap game and a U.S game and you want to save in both of those, what i do is i copy the memcard in a different folder and name to folder Jap/U.S/whatever and i just change it depending on what game i want to test/play
If you are not then, let me ask you, "Are you in the right forum?"