Macro to re-roll dice but only a specified limited number of times

I would like to roll 5 d6s scoring successes on 4+. Easily done- but then the players have a limited by number of times they can re-roll dice that come up as failures which is dependent on their skill. So for example if your skill rating is 2 then you are allowed to re-roll 2 dice that come up 1-3. In contrast if you are unskilled and facing a more skilled opponent you have 'negative re-rolls' which force you to re-roll successes a specified number of times depending on how powerful your opponent is. Any clues how to do this please? Many thanks in advance

Unfortunately, this would require an API script or a custom character sheet. I can't see a way to automate this with just macros.

This should work for rerolls of either type /r (5+?{Rerolls|0})d6>4k?{Reroll Type|Positive,h|Negative,l}5 This does assume that you keep rerolling as long as there are rerolls left until your have 5 successes or failures

Wow thanks RainbowEncoder that worked perfectly!