Lester spent three and a half years at the City Ground and was a fans favourite, but was released from his contract a day after they lost to Sheffield United in Play-Offs.
So far this season Lester has notched 10 goals, making him top scorer. He now plans to do something that United aren't good at, a win at Forest.
"Whilst it's not a dream tie for everybody else, personally speaking, it's a good one for me," said Lester, who still lives in Nottingham. "I can understand why some people would have liked a big Premiership club but for me this is probably the best of the lot.
"There's not a player around who wouldn't want to go back to their old club and try to show them what they are missing. Nobody wants to fail in front of all their family, friends and old team-mates."