First of all tell ur friend to meet the girl's family and talk clearly about the issue.let them know that its not only urfriends younger brother involved but also their daughter involved...

Later let ur friends family tell the girl's family to allow to let both girl and boy talked on phone...no matter how many times....let parents clear that not to let them meet let them talk atleast....tell ur friend and his family to sit and talk to the boy to understand and assure him that they wont oppose for anything....let them make it clear to him that once he is settled in his job well then they would surely get them married...

same applies to the girls family...let the parents of girls clearly make thier daughter understand and let her talk her on phone...to avoid ugly situationss...inshallah everything would be allright..

whatever happens let the boy's parents and girls parents be in touch everytime....

lastly make it clear for the girl and boy that they are really in love with each other and will not cause any problem in future if any let the both parents make it clear that if any problems dubai has big building and also has trainsss so they can either jump or get under the train no worries(just kidding :) :) sorry no hard feelingss,,..(.this was said to me by parents)

last but not the least pray and also tell ur friends family to pray as he almighty is the only one who would help and guide....

take care