I... am at a loss for words. Do you not realize how terribly bad of an idea this is?
Honestly, I don't know if Cognos can do this (I hope it cannot). But let's assume it could, and you achieved it - what would that leave you with?
Either, the "dynamic" passwords per user are generated by some sort of logic as to how they are generated. Then, as the users need to know the same logic to know their own password, they will be able to work out *other* users' passwords as well.
Or, if they are not generated but user-chosen, that leaves you with at least one place where a collection of user passwords are stored in plain text.
Either way, implementing this would lead your users to believe in a systematic security that *SIMPLY ISN'T THERE*, and possible security faults of that system would be *YOUR* faults. Do you want that kind of responsibility on your shoulders?