Hey, Dan. Perhaps you can send a sample of what you did get to work. In the meantime, I too have struggled with reminders. The options only let you choose one specific number of days. I always wanted to select options like "Before Today" or "During" a time period, etc.I got around this by making a formula date field and letting it do all the work. I name it "Reminder Date". I wanted to send out a reminder for all overdue tasks. My database has a "Status" field and a "Scheduled Date" field. Here is the formula I used:
If([Status]="Scheduled" and [Scheduled Date]<Today (),Today ())
So this says that if the task is scheduled and the scheduled date is before today, display today's date. So now, all my overdue tasks have a Reminder Date of today.
I then set up the reminder to remind me 0 days before the Reminder Date. Using this as my standard reminder set up, I can then modify my Reminder Date formula to show me whatever you want.
If this is gibberish, send me your sample and I will try and help.