you already found something for that ?
Here was a thread on the forum on that. you would need a hexeditor (WinHex or Hex-Editor mx or similar)
I also can confirm that changing those letters P to E (in hexeditor) and using the different folder afterwards / or changing the last digits in the folder name from 50 to 45 should do the job.
hope that helps
edit: also if you dont see those folders, there is a pc utilty to unpack the savegame stuff, get it at wiibrew its called FE100