Searching all open modules

Hi Folks,

Pardon my newbie questions:

Background: i am writing a new search plugin for Java development (please correct if this is not the right forum)

1. How do i search for a particular Field in all the open modules in the IDE.
2. Once the user clicks on a particular field (i have that working using the sample CopyFQNAction plugin), i would like to display a new button.

Thanks,
Sunil