start-search is an event on the browser , which occurs when you click the column-label.
You will have to write code to do a filter (where clause) or a sort on the browser query within the start-search trigger.
In my experience , START-SEARCH is best used for sorting the column / browser data, (I have used it earlier to sort the data in ascending or descending order).
And for column data search . Use a fill-in above the browser column and use the triggers like any-printable to update your query.
Cheers
Sunil