1.) Download Nestopia, extract the folder onto your desktop.
2.) Download Earthbound Zero from wherever you want, and place it onto your desktop.
3.) Load it with Nestopia.
4.) Get to the point where you save in the game.
5.) Exit Nestopia to create the save file.
6.) Look in the Nestopia folder, and look in a folder named 'saves'
7.) Earthbound Zero.sav should be in there.
8.) Transfer the .sav and .nes file over to your MicroSD.
9.) Ta-da! Portable Mother!
Have fun.. I can't upload the save file because I don't have my DS here at the moment, and all my saves are on it.