In the Dominican what?????????????
"Dominican" is an adjective and cannot stand alone. Unfortunately, the founding fathers did not realize that the world would produce such connectivity and they named the place the Dominican Republic to distinguish it from the Venezuelan Republic or the Colombian Republic of the times.
GRAMMAR POLICE: Out!
to answer your question: You can exchange you money here in the DR very easily at any one of the many "Casa de Cambio" that pop up like mushrooms.
You can do it at any of the commercial banks, too, but you will get a slighly less favorable rate.
If you do not want to bring a lot of cash, bring your plastic, but not your debit card, your credit card...Stick it in any of the hundreds of ATMs around and voilá: money.....
Have a wonderful time in your first of many visits to the Dominican Republic.
HB