Ouch. 
um... Ya, that's waaay too complicated for the scope of what I want to achieve. And, it still wouldn't provide the right result...
Part of the problem is that the additional damage is tied to both the level of the PC and whether or not the ritual for the weapon has been achieved.
I'll list the level-dependant elemental damage as a weapon special, that way it'll at least show up on the character sheet.
Hopefully the d20 system gets that upgrade soon(ish). I guess I'll have to start paying attention to the changelogs!
Thank-you for all your help, Sendric!