The procedure to highlight hits in a local PDF file that was retrieved in a search is as follows:

1. Call SearchResults.MakePdfWebHighlightFile to create the XML stream with the highlight information
2. Create an lbvProt.LocalProtocol object (this should be done once per application instance, so the created object should be kept in calling application until the application exits).
3. Call the object's MakePdfUrl method with (a) the name of the PDF file, and (b) the highlight data. It will return a URL that can be used to open the PDF file with highlighting.
4. Use the WebBrowser control's Navigate method to navigate to the URL.

In a .NET application, add a reference to the lbvProt.dll component to your project to access it using COM interop. 

C# Sample (using COM interop)  

if (pdfHighlighter == null)
    pdfHighlighter = new lbvProt.LocalProtocol();
String hl = searchResults.MakePdfWebHighlightFile();
String url = pdfHighlighter.MakePdfUrl(searchResults.DocName, hl);
webBrowser.Navigate(url);

Highlighting hits in PDF files