At the bottom of the Spreadsheet Style log system is a navigation bar of which contains an icon looking like binoculars. Click this for search functionality. We do plan to improve the search engine in the next version of Logbook Pro. You may also want to investigate the Route Browser for additional routing analysis features.
You can use wildcards, it should not be case sensitive, you would want to use the partial match option. For example, if you are searching a route of KLAX you could use a search of *LAX to locate the items.