Dolphin Netplay Save game progress with friends

[CynicalDylan]

So me and my friends want to play co-op games and save our actual progress for both Wii and GameCube games. My question is how do you do this or is it even possible? I see on netplay their is a write to memcard or SD card option but whenever we get to a point to save we get nothing when we relaunch the game.
Help would be greatly apprecative