setting alerts by subject

Is there a way to set my iPhone to set off an alert based on words in the subject of a message?

I belong to an emergency response group, and alerts are sent out by messaging (text). There are an changing array of people who can send out a call, but the subject always contains the text "[callout]". I need to be able to set an alert based on the subject text to trigger a special ringtone so that I know it is an emergency message coming in.