Changing Outbound caller ID (ISDN lines)

Dear All,
I’m in Switzerland, using a Asterisk 1.0.9-BRIstuffed-0.2.0-RC8p , and 'im trying to change the outgoing CID to use one toll free number we rent.

We are using 4 ISDN lines .
-3 are grouped in a “cascade” ( i dont now the term in english): 3 lines (2*3 channels) with only one incoming number xxx-7810 (ISDn point to point).
-1 is used with a standart BRI (ISDN point to multipoint).

For the “cascade” we rent 20 numbers xxx-7810 to xxx-7829 and for the BRI we rent only 3 numbers xxx-2740,xxx-2741 & xxx-2742

I tried to set our CID to one of the rented numbers, no way, the CID is still the same : xxx-7810
I tried with setCallerId and setcallerpres, but witout sucess.

Any idea ?
Tghnaks in advance

extensions.com (part)

to dial out
exten => _0X.,1,SetCallerID(0844267840) // general office number
exten => _0X.,2,Dial(ZAP/r1/${EXTEN},60)

zapata.conf (part)

usecallerid=yes
usecallingpres=yes

You have to talk to the phone company in order to be able to change your outbound callerid at will.

If you think the phone company is sloppy, then google “spoof callerid asterisk”

and look for cidspoof.agi

You can also look at this link: rootsecure.net/?p=reports/callerid_spoofing