Getting archive pages in WP's AJAX internal link finder?
marked as duplicate by Rarst♦ Aug 2 '11 at 9:03
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
Right now there are no hooks to do that from a plugin and the function that makes the search query itself is not pluggable which means that the only way to achieve that is to hack core files.
Currently there is an open Trac Ticket asking for some kind of hook.