One extension, choose an CID on the phone

I have three external phone numbers (connected through SIP accounts). If a call is comming from external, I want to see that number (DID) on my dect phone.

Also, if I call from my dect phone to the outside, I want to choose a CID (or one of my DIDs).

The dect phone is connected through a SPA-3000 to a new freepbx server.

How can I do this?