Yep that was the first thing I checked. Netfilter doesn't support it. Can't hurt to ask if it can be implemented as a feature into the ERL 'configure' program.
You're right, the best solution for now will be to move the script to the edge router and add it to cron. Might have to play around with the whole configure; <make changes>; commit; save; exit process unless there is a better way to script changes to the configuration.
