Addition graphics style dirs?

[gizmo4321]

There are some graphics that don't have the ability to be modified by style; e.g. you can go into ACP->Style Manager->(style)->Style Vars and set the path to things like the Button Images Folder and the Item Status Icon Folder, but not the Rank Images folder (which appears hard coded to "images/ranks") or the rating folder (which appears hard coded to "images/ratings").

In digging through the templates, I see that the information used by the ranking system is injected into the HTML by $post['rank'] in the postbit template (as well as several other places).

Since I'd just as soon not have to modify 20 templates to accomplish my end goal, is there a central place I can inject style-specific paths for those directories that do not yet support such?

I'm guessing I can do this with a plugin that hooks at the proper point, but I haven't got the foggiest idea which hook point to use. Should I go with style_fetch, or fetch_userinfo, or one of the group-based hooks? I just don't know?