Reg. call forwarding

Hello all,

I need your guidance in my setup.

I have asterisk with E1 truck and IVR server. I wish to forward all calls landing to asterisk to my IVR server.

IVR accepts SIP packets dialed into to it DNIS. (1001)

calls landing in e1 at asterisk and it reaches the default s extension. i have created sip extensions for this DNIS. created the dial plan and sip extensions as follows

in sip.conf

[holly]
type=friend
user=1001
host=10.0.0.250 ; it is IVR server ip address
context=main
authname=1001
dtmfmode=rfc2833

and in extensions.conf

exten => 1001,1 Dial(SIP/holly,30,rtT)
exten => 1001,2,congenstion()
exten => 1001,102,busy()

when i dial from a one of registered sip extension of this asterisk to 1001, i get can get into the IVR server.

I just want to forward all the sip packets dialed to 1001 to ivr server. As per IVR, it does not reqire any registeration and pasword.

How could i go about it now?

Thanks,
Rizwan