Insert Custom Search Results from my Plugin

I’m in the process of writing a plugin that takes some xml files from a third party software and imports them into the WordPress database. This information is then displayed using custom template pages. All of that is working fine, but I’m needing to be able to search these custom tables for content and return them to the search results page.

From the research I’ve done it looks like most people do custom searching by building a custom search page and modifying the results there.

Is there an action hook that will allow me to inject search results into a WP Search without having to create a who new page for it? The default page is fine, I just want to be able to add results to the page from my plugin. Seems like this should be pretty straight forward, but I’m not finding much outside of the whole new search page line. Any guidance is much appreciated.

Thanks!