Launching external application from browser

Dear Group,
I need help regarding an application feature i need to develop: I basically have to load a webpage in my browser, and clicking on a button in the webpage, i get binary data that must be sent as input to a local machine application , which then processes the data.

  1. Do i use a browser extension, or an NPAPI plugin to achieve this?
  2. Does the JUCE Framework have the capability to send a trigger to the application, thereby launching it and sending it the binary data stream?
  3. Can anyone please suggest an outline of control flow (sequence of execution of component steps, similar to a flowchart/UML sequence diagram)