Macro Math

So I have this Macro: !token-mod --set bar1_value|-[[20-@{target|Resist}]]  --ids @{target|token_id} It applies 20 damage to a token from bar 1 - minus the token's Resist stat.  Easy enough. If I have 0 Resist points, I take 20 damage.  If I have 20 Resist points, I take no damage.  The challenge is: If I have 30 Resist points, I heal 10 damage and that's not what I want. Ideally, if you have more Resist points that Damage points, you take 0 damage.  Thoughts on how to manage this? Thank you

(I tried looking this up myself in the conditional math wiki, but was overwhelmed by all the formulas)

use keep/drop logic for this. [[{[[20-@{target|Resist}]], 0}kh1]] If the number goes negative then it keeps the 0.  Example: 20-30resist = {-10, 0}kh1 = 0

Thank you!