Macro help

ok so currently I have the Following macro Created  &{template:default}{{name=Overrun}}{{Hit:=[[1d20+10+?{Hit|0}]]}}{{Dmg:=[[6+?{Damage|0}}]]}} I am trying to add an addendum where it takes the result of the Hit and displays it again with a -5 with a note attached to it

Unfortunately you cant reuse the results of rolls, or display them a second time. The best that you could do is just put another entry beneath it, iwth the -5 and let people apply it manually. Like  &{template:default}{{name=Overrun}}{{Hit:=[[1d20+10+?{Hit|0}]]}}{{Note=-5 note here}}{{Dmg:=[[6+?{Damage|0}}]]}}

If by "Hit" you mean the roll query, you can reference it again in the same macro as ?{Hit}. A query is filled in once and then the same choice is used for every instance thereafter. If however you mean the result of the calculation: [[1d20+10+?{Hit|0}]] That cannot be used again. Roll20 dice rolls are "fire and forget". This would only be possible with a roll template (baked into the character sheet), or an API script of some kind (Pro perk).