I don't know specifically what country you are referring to, but I can guess that the currency is probably pegged either to the U.S. dollar or is The CFA. They are exercising a fixed exchange rate, and probably have a centralized, controlled monetary system. Therefore they struggle with capital controls. That's why the black market is flourishing, if you accept the trilemma theory. Practically speaking, you have a great plan. I have no idea how to implement it, though!