Random play from one audio file in time increments - I'm a Max newbie

I've been trying for several hours after going through tutorials and trying and testing... hoping someone can tell me where I'm going wrong.

My audio file is too large to upload here, but I have included the patch to plead for help. What I'm trying to do is get 8 seconds bits (8000ms) of one audio clip (which is 598800ms) randomly and loop infinitely. Instead, what I'm getting is more linear play of the audio and only occasionally does the clip actually change when the "loop start time" number changes.