Macroing to Check for Doubles

Hi friends. I am currently working on a way to make the Mistborn Adventure Game work well in roll20. The dice system is d6, where you roll your pool of dice and then check for doubles. Is there a way to check for that in the roll request? (To make things more difficult, 6's don't count towards the doubles thing, so it can't just be "check for the highest set of doubles.") The closest I've gotten is /roll Xd6sd to make them go in descending order, and then ignore the sum of the dice that the program automatically gives.

That's the only way I can think of without using the API, which is a Mentor-level feature

As no one has the money to spare, that'll have to do. Thanks much.