Redmine

Good Afternoon

I'm currently developing a plugin for redmine and I'd like to extend the currently implemented search funcionality to allow it to do a custom search on some of the (rails) models defined on the plugin. From what I've seen, the currently available search sources are statically defined around line 51 in the search controller.
Is it possible to add new search sources directly from the plugin into this controller (ie: from init.rb), or would I have to create my own controller inside the plugin?

Redmine stats:

About your application's environment
Ruby version 1.8.7 (x86_64-linux)
RubyGems version 1.2.0
Rails version 2.1.0
Active Record version 2.1.0
Action Pack version 2.1.0
Active Resource version 2.1.0
Action Mailer version 2.1.0
Active Support version 2.1.0
Application root /home/amp/Aptana Studio/redmine
Environment development
Database adapter mysql
Database schema version 101

Currently running under webrick

Thank You

Yuri