Custom dice syntax; a flexible alternative to rollable tables

Currently the only way to get custom dice is with GM-only creation/maintenance of rollable tables which have to be customised for every possible combination of modifiers, target values, etc.

I suggest that custom dice could be defined in macros using a comma separated list of values, ranges, and dice expressions each with an optional colon separated weighting. Some examples:-

Some amount of d10's with a minimum of 3 could be defined

?{How Many}dC(3:3,4,5,6,7,8,9,10)

Some amount of 1d4+1, useful for magic missle

?{How Many}dC(2..5)

Some amount of 2d20k1, useful for mob attacks with advantage

?{How Many}dC(2d20k1)

A few things to note

• negative values should be allowed
• weights of zero should be allowed for easier attribute/calculation based handling
  
• a range could represent a single value eg. 6..6
• a range could be written descending eg. 6..1
• a range could have a weighting in which case each element in that range would have that weight. eg 3..6:2
• ranges could overlap
• dice expressions could have a weighting and would be considered a single element for that.

This would also be great for any Character that has a feature that offers a minimum value for damage dice.
So for example in D&D 5E one could simply use a dC[2,2,3,4,5,6] instead of a d6 on a Caster that picked the Elemental Adept Feat for Fire and is casting Fireball (and all other Spells of that type to have it automagically apply)!

Cross suggestion potential: Rollable tables with modifier/advantage/as lookup

Some concrete examples of how this could be used:-

To solve the suggestion: Cyberpunk Red crits & fumbles

1dC(1-d10,2..9,10+d10)

To solve the suggestion: Open-ended roll support

1dC(d5-d100!>96:5,6..95,95+d5+d100!>96:5)

To make group-sum target comparisons easier for: Better GURPS support (No more dummy values)

dC(3d6)<12

I would love to be able to customize the values of certain rolls in dice. Like custom fate dice, where you can assign any value to any number. I think it would simplify a lot.