Java for custom email reminder

Hi, I am using a survey to schedule appointments and want to have an email trigger that sends out a reminder 48hrs before the appointment. Support told me the only way to do that is to set up a quota for each and every day we would have appointments (roughly 300 days a year) then the email trigger would send when there were appointments on those dates. Does that sound right? Not really practical to set up 300 quotas. They said it might be possible to write Java Code to do this but I barely know enough to cut and paste Java into my questions (I got a custom calendar to work, yay.) Any help would be greatly appreciated!