Communicating with externalResource


I have a vaadin application with an embeded external resource which performs some search functionality for the main application. I need to be able to send parameters back to my vaadin application from this resource.

So basically the scenario would be:
user navigates to the search screen (an external 3rd party app)
user finds a specific id via the search and clicks submit
the external app navigates to a given url with the chosen id as a parameter
main app can read this parameter and do something with it (change views)

I have not been able to think of a way to accomplish this. Is it possible?