Agreed that there's more detail necessary to answer.
But consider that if you are using this to trigger an AO profile, instead of on arrival, use a non zero overdue age. Then you'll only get an alert on that over due age past when the alert arrives the first time. Then if you want weekly, set up a scheduled job to close cases open for 7 days. You'll get a new alert the next time CDM looks at the drive and the AO will fire again.
Or run a script weekly to do whatever on any matching open alerts.
-Garin