From a great site, Greatest Hockey Legends, here's a good story about Darren Helm having tied the record for most playoff goals scored before getting a single regular-season goal. Helm shares the record (four) with Montreal's Eddie Mazur.

http://www.greatesthockeylegends.com/2009/05/darren-helm-modern-day-eddie-mazur.html

From hfboards.com, here's a list of the leaders in that category ...

4, Darren Helm
4, Eddie Mazur
3, Bill Guerin
3, Marc Bureau
3, Perry Ganchar
3, George McPhee
3, Ray Cote
3, Bob Gould
3, Kevin Maxwell
3, Walt McKechnie
3, John Harms