[Calipher]

I was thinking about working on the same idea, and while poking around I found this in nUI_UnitFrame.lua. It might be what you're looking for, Xrystal.

		if unit_info and unit_info.max_health and unit_info.max_health > 0 then
			GameTooltip:AddLine( ("|cFFFFCF00%s:|r %d/%d (%0.1f)"):format( nUI_L["Health"], unit_info.cur_health or 0, unit_info.max_health, (unit_info.pct_health or 0) * 100 ), unit_info.health_color.r, unit_info.health_color.g, unit_info.health_color.b );
		end
		
		if unit_info and unit_info.max_power and unit_info.max_power > 0 then
			GameTooltip:AddLine( ("|cFFFFCF00%s:|r %d/%d (%0.1f)"):format( unit_info.power_name or "", unit_info.cur_power or 0, unit_info.max_power, (unit_info.pct_power or 0) * 100 ), unit_info.power_color.r, unit_info.power_color.g, unit_info.power_color.b );