Here is the contact info
Embassy of Belgium in Dominican Republic
Apartado 1221
City: Santo Domingo
Phone: (1) (809) 544.22.00
I would suggest calling them and ask what kind of visa he requires or call your own government and ask what the requirements are.
That being said, he can't just come live with you without going through an immigration process. He might be able to get a visitor visa for 90 days. I don't know how strict your country is about issuing visitor visas.
http://www.diplomatie.be/en/travel/v...sp?TEXTID=1180
Good luck