dialer addin api for external application

Hi all,
I need to integrate a jsp-based web application with outlook dialer
add-in.
Users should be able to click on an icon next to a phone n. in the
application screen to start the call.
Can that be done (e.g. via some kind of API)? I would highly value any
hint or useful resource.

I am totally new to outlook addins so please forgive me if my
questions are very basic.
thanks and regards

Vincenzo Turco