Using mapping as a comparator

[ohho]

I'm trying to use the mapping to detect when a certain cv signal (in this case an envelope) goes over a certain value, and when it does go above that value I'd like to output a trigger\gate.

See video at the link below for further explanation and question
https://www.dropbox.com/scl/fi/cqbbqml39...m7r4j&dl=0

Thanks!