[Kendian]

Waky was kind enough to work on this and send it to me in a pm, wanted to post the end product, to show appreciation for his time and effort, this text string is pure coolness~

function(unit, cache, textframe)
if (UnitAffectingCombat("player") or GetMouseFocus():GetName()==("Stuf.units."..unit)) then
  if (cache.perchp<99) then
    return string.format("%d%%%% > %d",cache.perchp,cache.percmp);
  else
    return string.format("%d > %d",cache.curhp,cache.percmp);
  end
end
end

You'll have to check both frequent updates and show only on mouse over for this to work.