I figure that it would be possible to create tokens for characters and such. Though I'm not sure how much The Haunted Tower relies on materials from the base game.
It says right on the back of the box "To play the giant three-part adventure, you must own the Dungeons & Dragons game. The bonus board game is playable immediately." I would think that at the very least you'd need the rule book from the core game and a full set of polyhedral dice to make things work properly if you wanted to play the three-parter.