Possible Kill counter?

[Randymarsh9]

I was wondering if it was possible to have a system to keep track of how many monsters someone has killed for a quest. Por examplar, tracking to see how many guards someone has killed in highkeep and when it reaches 10 enable them to get a reward from an NPC. I was wondering if it was possible to do something like this by making the game add a flag for every guard killed onto the quest, and when it hits 10 they can get the reward by the npc checking their flags. I need to ask this because I have no experience doing anytihng with flags yet.