Lists inside gen~?

So a little while ago i read something about using buffer~ to store a list and then reading it from inside gen~, and now im trying to find more information as to how i could implement this, my goal is to build a delay circuit whose time is changed every time the input passes a certain threshold, i made a list of the numbers i want to use as time but am unsure as how to proceed so as to be able to store the list in the buffer~ , and then everytime the audio input signal goes above a certain threshold a number from the list is chosen at random then this number is used as the value for the delay time.

Does it make sense?

help?