I'm working on an addon that will keep track of alts based on which characters are uploaded together. Basically, if a bunch of characters are uploaded in a single CharacterProfiler.lua file, it flags them as alts of the highest level character in the file - I'll add capabilities to edit who's the main once everything else is working.
I have the code to store alt information in the database working, but would now like to add a column to the roster list to show who the main of any character is. I can do this with my addon by adding a FIELD[] variable, and respective display and divider functions, then including the memberslist.php file to do the actual work. This works, but when you click on the headers to change the sorting, it bombs out because it tried to reload the roster from addon.php rather than index.php. Then I thought perhaps I'm missing something, and there's some built in mechanism to allow addons to add additional columns to the main roster listing. My only other alternative at this point would be to modify WoWRoster's main index.php file, which is something I would rather like to avoid.
Anyway, if you want to see what I have so far to get a better idea of what I'm talking about, you can look at http://www.servantsofseagis.org/roster/addon.php?roster_addon_name=altmgr. Thanks!