If you are going to do business here in the DR, you can incorporate with anything from 1 to 7 foreigners. (If it's just you, your attorney can or will provide 6 "partners", with undated letters of resignation. It is necessary to have 7 partners to form a company here, and at least 2 after that point to maintain the company as a "legal" company in the DR).
It doesn't matter if there are any Dominican citizens as a partner, and if none, I think they use one of the partner's passport number as a referenced # attached to the company.(instead of their cedula #)
By incorporating in the DR, your entity is on equal legal status as any other DR-incorporated company, if you want to go to court, or need to answer something in court. You also receive an RNC number which is necessary to do business here, and to pay whatever taxes the company may be subject to, such as payroll, ITBIS, or company income taxes.