maybe you should implement search in the database instead of integrating it in site search. You "could" implement it in site search but if all the items are on the same page in the same grid then the search result is just going to take them to the page with the grid on it. If you want to search for specific rows in a grid it seems better to to that in the database, like we have member search on the member list and we have searching of items in Content Manager page, both of these are done using the database not the site search engine.
Hope that helps,
Joe