What I usually did (but this was back in TK2) was make programs that have a conditional activation, and made them appear as a closed chest, and on the board I put the tile of an open chest underneath. I don't know if it works like that anymore since I haven't used TK3 much for a while, and I never completed a game with TK3.
Maybe what you could do is just post your code, it might be some error me or somebody else can point out.