Asterisk script/code for contest/game of chance.

Asterisk script/code for contest/game of chance. Contest or game of chance. Callers hear an introduction Callers hear a sound file that changes by the hour. I should be able to put as many or as few sound files here as I want. I should be able to say at what time each sound file plays. Callers hear that they have not won and should call again. Caller number X hears that he/she has won and is taken to voice mail to leave contact info. I should be able to change what number X represents. I should also be able to change how many winners I have in an hour. I already have a working asterisk PBX. I would prefer something with an easy admin interface as opposed to code that has to be manually changed in the dial plan.