OT healing

[Leroy]

So i play an OT and the potions for healing HP and MANA are not the same as rl tibia. i know you can add that in macros, i just dont know how id make this. its a high exp server so my mana is around 2billion and advances rapidly, i need a script that goes by percentages (if possible). so like when my mana is less then 99% full it uses object 9112 (i already checked the id).
If someone could help i would greatly appreciate it.
Thanks!