Open Ended and Under Ended Rolls

For the system I'm using, it uses d100 and open and under ended rolls.  That means if you roll over a 95 or above, you roll again and add that to your roll.  I can accomplish that with d100!>96.  But if you roll under a 5, you roll again and SUBTRACT that from your roll.  The problem with the exploding dice formula is that it still adds, so d100!<4 will add the 2nd roll to your first instead of subtract it.  Any suggestions?  Can the devs add a new method of "imploding dice" maybe?  :-)

What I end up using for my games is:  [[1d100!>96cf<5cf=66cs=66cs=100 (+modifiers etc) ]] and then looking for the red to know that I need to roll an additional 1d100!>96 and subtract it from the original value.    This particular roll will be coded red (failure) for a <5 (that's the cf<5 part),  it will be coded blue (mixed) for a natural 66 (that's the cf=66cs=66 part) and will be coded green (critical success) for a natural 100 (that's the cs=100 part). Obviously if you don't need the color coding for the natural 66 and 100, you can ignore those parts of the roll. :) When I'm being lazy, I run a second macro which looks like:    final result: [[?{OELow roll?|0} - (1d100!>96)]] otherwise I just do the subtraction manually.  :) Hope that helps.