Combatlog parsing

[Rince]

Well i need some basic help on how to parse a combatlog.
I already tried http://www.lua.org/manual/5.0/manual.html#5.3 but i just dont get the clue.

Looking at other mods didnt help aswell

Here is what i want to do :

if (event == "CHAT_MSG_SPELL_SELF_BUFF") then
*insert parser*

amount_healed = parsedx
player healed = parsedy

I know to solve my problem it would take a whole tutorial, but just give me an the first 1 or 2 steps. Editing it later for crit etc i can do myself .