Dexter - the 20-year-old son of recently-introduced character Ava - turns up on Albert Square next week as he is keen to get to know the Branning family.
While Ava isn't pleased by Dexter's antics when she finds out, the pair later relocate to Walford as Ava lands a new job in the area.
Best told All About Soap: "Dexter's pleased when Ava tells him she's got a job interview in Walford. He's looking forward to moving there, because it's a new start for him. Dexter hasn't had the easiest of times, but he's coming out on top now."
Dexter also finds a job in Walford when Phil Mitchell offers him a position at The Arches.
Best continued: "When Dexter first meets Phil, he doesn't know who he is, but he soon understands his position of power and works out a way he can best manipulate that."
Ava, Cora Cross's long-lost daughter, made her first EastEnders appearance in November. Executive producer Lorraine Newman has now confirmed that she intends to set Ava and Dexter up "as a unit of their own" in the coming weeks.
Newman told the official EastEnders website: "Both Ava and Dexter will be involved in a big story with Bianca [in 2013], which will help to introduce them both more into the Square. Dexter will also start working as a mechanic in The Arches, and he and Jay will become very good friends."
EastEnders airs Dexter's first scenes on Monday, January 7.