Set BAB to Caster Level for 1 weapon in editor

[dangermouse]

I have been trying to add Mage's Sword as a weapon through the editor but can't figure out how to change it so that it uses the caster level for the BAB for that single. I tried setting the BAB to the Caster Level and it did nothing. I experimented with changing the BAB in the PreAttribute phase but change the BAB for the entire character. I still couldn't get the caster level part to work.

I would be happy with calculating the difference between the caster level and BAB and adding it to the weapon as a bonus to hit but I can't figure that out either.

Anyone have any suggestions?

[dangermouse]

So I figure out how to do the calculation to change either the BAB or just add a competence bonus which is the difference of character level minus BAB. The issue I have now is that it applies these changes to all of the attacks, not just this one weapon.
I put this code in the Post Attributes phase:
hero.child[Attack].field[BonComp].value = (#totallevelcount[] - hero.child[Attack].field[tAtkBase].value)

Anyone know how I can make this apply to just this one weapon?

[dangermouse]

I think I got it. It adds the difference of the character level and BAB as an untyped bonus for the single weapon I created, which works close enough.

hero.child[wMageSword].field[Bonus].value = (#totallevelcount[] - hero.child[Attack].field[tAtkBase].value)