Setup a Lync Call between Lync user and external number

Hi,

We want to create a service that can setup a call between a Lync user and an external phone number.

Somewhat the same principle as how the Lync app for tablets starts a call. With the only difference that the Lync app setups a call between two mobile numbers and we want to setup a call between our known Lync number (user) and a external number.

So the service should call our Lync user, when this user answers the service should setup a call between this Lync user and a external number.

We cant find any helpful resource at the UCMA 4.0 Samples or on the web.

Is it possible? And are there perhaps any examples that could lead us in the right direction?

Thanks