search module customization

can any body help me to customize search module, i basically want that when i search some keyword it search it from gallery2 as well as external source(it can be another site where images are hosted, basically i will hit webservice and call some specfic method which will give results and based on that i want to render it on gallery2 search result page) and render the results.

is it possible using Gallery2, please guide me i am newbie to gallery2.

Thanks in advance.