[Phanx]

Yeah, so just replace the part that queries combo points with a UnitBuff query, and the part that registers combo point events with a UNIT_AURA registration, in addition to renaming the element itself.

Also, please stop wasting resources looking up the buff name with GetSpellInfo every time UNIT_AURA fires -- look it up once and store it in a variable:

local ANTICIPATION = GetSpellInfo(115189)

local function Update(...)
   -- use the ANTICIPATION variable in here
end

and also stop wasting CPU time on calling select -- just ignore the first three returns:

local _, _, _, stacks = UnitBuff("player", ANTICIPATION)