Will you get 5 volts if you give 5v to a 220to5v charger?

Get a couple books on building power supplies and you will be set

Building specialized supplies can get rather involved, but general "everyday" stuff is pretty straightforward and quite cheap.

Even if not books, there are enough totally free resources to get you on your way.

That said, DO NOT mess with mains voltage if you don't know what you are doing. And even once you DO know what you're doing, never, ever take it lightly. Raw mains voltage is tricky enough, once you start messing with it beyond that it can get very deadly, very fast and in ways that can hurt others as well as yourself.

Its one of those things that if you have to ask, you probably shouldn't mess with it. Luckily though, what you are looking to do is pretty basic and you can get up to speed pretty darn quickly.