How did the president of the DR helped on the conflict with Colombia and Venezuela?

To what conflict specifically are you referring? The last conflict I remember was in Cancun, Mexico, during the Grupo de Rio Summit. On this occasion, president Leonel Fernandez tried to discourage Colombian president Alvaro Uribe from offending Chavez. Fernandez knew Uribe was planning to interrupt and start to provoke Chavez. The request of fernandez was obviously ignored by Uribe, who interrupted the summit to insult Chavez by telling him "to be a man", one of the most insulting phrases you can say to a Latin American man.