macro for specific pathfinder ability.

i have a rogue in my party that just started playing in a high level campaign of mine and he chose a mythic ability called fickle attack. i wish to make it easier on him by making a macro that does the hard stuff for him but im having trouble figuring out the math based conditionals. the ability reads as follows: Fickle Attack (Ex) : Whenever you roll damage for a melee or ranged attack with a weapon or alchemical item, you can treat any natural 1s on the damage dice as if they were the highest possible number on those dice. You can select this ability up to three times. The second time you select it, treat 1s and 2s as the highest value. The third time, treat 1s, 2s, and 3s as the highest value. does anyone know how i might put this into a macro for him?

what im tinkering with currently is kind of a mess. this is what it looks like. /r [[ { {[[6d6<2]],3}<2 }*(6) + [[1d4 + 2]]]]  this is definitely totally off but every route i go i run into the same problem. there is no way to store inline numbers. i cant do this: /r (1d6)* (number that i rolled). so in this example it just squares the number. unless im missing something i doubt i can make this macro happen. which will slow my game considerably due to my rogue having 6-7 attacks per round and all will likely be sneak attacks.