It doesn't currently exist, but it is certainly possible.
... That being said, I don't think that adding hit to existing weapons should be a result of merely farming items, especially ones from quests that are already spammed to death anyway.
Since I don't want to seem like I just completely shot down an event idea:
Consider changing the quests/monsters involved. Preferably monsters that don't spawn too often in TTF/RT or even POD.
Consider a different reward --donations keep the server running. Besides, many people have traded a lot to get a 40 hit weapon, and then its value would drop considerably with an event like this.