Ok, let s say you can change the policy about dollars: what would you do?
Thats pretty easy, allow the purchase and sale of dollars (and other foreign exchange currencies), legally. And allow the "official" exchange rate to float properly.
If you want, you can restrict the transaction of these foreign exchange currencies to those that have their house in order with AFIP (I actually wouldnt mind seeing atleast that so a measure to try and reign in tax evasion).