You go to hockeydb.com (or hockey-reference), get the roster of that team during that season (99-00). Your player pool is any player who played at least one game for them, playoffs included. Then you are allowed to draft any season in those players' careers - that's what we call "twist".
So say for example, you get the Penguins, Jagr's on the team... you can use a Jagr from the early-90s Cup-winning Penguins, or from the Rangers if you wish.