Hi Nicole, and welcome to the forum.
It would help if you could please [URL="http://www.monarchforums.com/showthread.php?t=2290"]post a sample of your report[/URL], and perhaps describe the trap that you're using in your detail template.
Then it will be much easier to assist.
Also, are you using the V9 Standard or Pro edition?
I'm with Kruncher in suggesting that seeing the report sample would be useful but I think I know what you mean by the MCR facility to define when a template should stop and start and I'm not sure it's quite the same thing as you need here.
Basically is you have 2 sections of the report that will always be picked up by a trap, as you have, the way forward would be tpo use the trap and look for something by which you can filter to keep and work with just the rows you need.
You might be able to filter the extracted table data based on;
/LISTThe section heading "Grand Totals" might work for you in this instance if the unrequired lines would capture something different or perhaps nothing.
It will be good to see the report shoud none of these suggestions (or something similar) work for you.