Add Armor Locations?

[velinion]

Short version: How do I add new Armor Locations to the editor's choices for new armor?

Long version:
I am trying to add all the armor (and eventually all other equipment) in Arsenal, and have a problem. Much of the armor is meant to be worn as a "set", with their protection being additive (instead of only the best counting, as normal).

To some degree, this can be accomplished by choosing an "armor location" in the editor, but the only options are "Full helmet", "helmet", "mask", and "shield".

A suit can technically be done this way by setting the pants as the armor, the shirt as a helmet, the jacket as a mask, and some other item as a shield, but I would much rather simply define some new armor locations, such as "Pants", "Shirt", "Jacket", etc. especially since some (eg. Form Fitting Armor) can explicitly be worn under any other armor suit with additive protection.