I've come up with the following ways to get around it, but I'd rather pull it off as imagined if I can:
- Find the player's current weapon skill and then use the appropriate 'Fortify Skill' effect to boost it. The problem with this is a RP one - using a stone on the weapon wouldn't increase your skill with the weapon, it would increase the effectiveness of the actual weapon. Also, this effect wouldn't stick with the weapon, it would affect any weapons of that type used by the player for the allotted time.
- Use the 'FDamageWeaponMult' setting to increase the weapon's damage multiplier. The problem with this is that as I understand it, using this will increase the multiplier for ALL weapons, not just the equipped one. Obviously, that won't work.
So... any one care to wager a guess? A scripted effect that will basically enchant that specific weapon for 30 minutes, increasing the damage it does by a given amount, but doesn't effect any other weapons the player has and doesn't require charges (lasts 30 minutes regardless of how much the weapon hits).
UPDATE: I think the attribute I want to increase is 'WeaponRating'. According to the damage formula on UESP, this is "the damage shown for the weapon in your character's inventory" and is the base for the damage calculation.