[Unsolved] -save command

I saw quite a few maps with -save command.It would save your progress,so you could play with the same things the next time you start the game if you type in -load.Can you tell me how -save and -load work?

EDIT:
Hellooooo?Anybody here?I really need the answer.Why isn't anybody helping me?

It's pretty simple, it just transforms all the data on the hero (unit type, level, attributes, items, abilities and so on...) to some code and then on -load transforms them back.
If you don't want to do it yourself, just try some of the systems someone already created, like this one.