Round Robin sample reset time knob

Hello! I am in the final stages of creating a metal bass guitar library, its a very simple library containing key switches for down picking samples, up picking and alternate picking. I have used other bass guitar libraries much like mine that include a knob labled "alt picking time' that goes from 0-600 ms. I assume this knob adjusts the round robin reset time. How might I script something like this within my library?