Pass Called DDI thru to Snom 720

Hi All,

I have installed a freepbx distro running Asterisk (Ver. I have a Snom 720 phone running registered to the Freepbx. I have programmed a DDI via Inbound route and made it ring to the Phone. This is successful. I am using call center software called ncall on my pc to connect via http to the Snom 720. This connects correctly and I have control of the phone via the Software as expected, answer,hold,transfer etc. When a call comes in via a DDI, I need to have the Dialled DDI number pass thru from the Asterisk to the snom and then have the snom deliver that DDI information to the ncall software. Currently it is only passing the extension number of the snom as the Dialled DDI?. from my google crawlings, I have found that I may need to create custom Extensions to force the Dialled DDI thru. Can anybody please advise me on how to get this sorted?