I think I've got it.
I've found the way out.
It's really simple, I can't believe nobody thought about it before.
It will be 1 coin = 1 usd/eur/... 100% secured by real money and with low fees.
I'm not a programmer or a developer...
I just need the answer of some tecnical issues.
Is anyone really  interested in this project (FIRST.CASH.TRADE.COIN)?

Ps. Sorry for bad English is not my native language.