Zenonia has three save slots, each of which corresponds to a file named SaveX.dat (Save0.dat, Save1.dat, Save2.dat). Before you restore progress, you must create a new game and save it, filling all the slots you want to restore from the backup.
I know: it's a little tricky. But if you don't want to root, thats the way to do it.
This application is experimental, so if you use it you could experiment problems or damages; use it at your own risk: I disclaim all liability for damages or problems caused from it.