Create Customized schedule for alerts

Hi,

I have set of servers that I want the alerts go as followed

I need the first alert to go after 5 minutes , then every 30 minutes for two hours , then every four hours till it recovers.

I tried some thing like DURATION>5 REPEAT=30m,60m,90m,120m,4h RECOVERED but it didn`t work..

Any ideas ..

Thanks

Tom