help searchQuery datatype with SearchMessages method

Hi,

I am writing an application which  needs searching users Yahoo mail messages.

I would like to search their inbox using search terms similar to IMAP seach client comand FROM "welcome@test.com" SUBJECT "Sample Subject" 

From documentation i understood SearchQuery data type is capable of handling that information.

Could any one please let me know how to use SearchQuery data type with SearchMessages web service call.

Thanks in advance.

Best Regards,
Mohan