How can I implement random character movement in the character blueprint?

Hi again ,

Just following on from this answer, is there a way that I could implement the random movement as you have outlined here, but stop and start it when an event takes place in the level or a key is pressed?
I need the characters to stop running when a mesh starts moving towards them but unfortunately I cant activate a custom event within the AI controller from my level blueprint, can you think of a workaround at all?

Thanks for you help.