You cant do this in roll20 with a standard macro. macros cant do conditional effects like "if the roll is 96+, do this thing, if not, don't".
For really simple situations, you can handle this with a Rollable Table. But if you want to do anything with the rolls between 5 and 96, like add a skill bonus or compare against a value, that won't work because the 96_+ and 5- results wont be reporting numbers and will break the macro.
I think the best you can do is use the critical marking system, where if you do something like
/roll 1d100cs>96cf<5
it will show the result as green for 96+, and red if 5-.
Note: in roll20 dice macros, > means "equal or greater", and < means "less than or equal".