NCM Scheduling a job every 15 minutes

I'm having an issue with a L3 switch which requires that I clear the NAT table every 15 minutes.

Is there a way to schedule a job in NCM to run every 15 minutes.

I've used the CRON expressions suggested with no success. 

  min                    hour  day  month  day of week

00, 15, 30, 45         *       *        *               *

I'm using NCM v7.6.0.1375