Forward DID Indication to Extensions

i’m trying to do a special deployment on FreePBX.
I’m running a VPS with FreePBX, installed via Script. All works fine and i can get trunk adn extension registered.
Since i’ve got some trunks, i need to manage them via DIDs and via Inboud Routes all works.
I run this to have a real mobility (my house dsl isn’t good so if i need to connect in mobility i don’t have to register to my home’s asterisk server but i will register to the VPS, that’s better).

After some days i find useful to install in my house an old Cisco SPA9000 (that i had in garage for some years) with six old SPA942 phones.
I use this SPA9000 with the PSTN (via SPA3102) registered as LINE2 and the FreePBX “trunk” via SPA9000’s LINE1.
All works fine, inbound and outbound, but the SPA9000 can’t manage the Ring Groups. This because it doesn’t receive the DID from FreePBX.

IS there any way or any workaround to forward the incomind DID to the extension? I don’t want to apply this rule to all the FreePBX’s exntensions (extensions that i use on mobiles doesn’t need it).

I’m running FreePBX and Asterisk’s version is 11.9.0
All runs on Centos 6.5

Thank you.
Alberto - Italy

Sorry, i missed to specify that the DID that i’m referring to is the Inbound one, the sam that FreePBX (Asterisk) uses to destinate the call.
So, i suppose, it’s the FROM_DID or a similar one.
The SPA9000 reads it as DIDN.

David55 on the Asterisk’s forum told this:
${EXTEN} on initial entry to the dialplan contains the DID number (assuming you have real DID, rather than a single number taken from an ITSP’s DID. Getting the initial ${EXTEN} under FreePBX is a question for the FreePBX people.

How you get that displayed depends on the outgoing channel technology and the capabilities of the phone. Some people use ${CALLERID(name)}."

How to implement this?

Any help? Thanks!