[OpenSIPS-Users] Sending call to extension to user

[Schneur Rosenberg]

I would like to send calls to a user that is registered to opensips,
the user is a PBX and I would like to send a extension like its coming
from a pri, basically its sending a URI to a registered peer, I cant
send a URI, because the ip address is not static, in asterisk i would
do dial(sip/pbxpeername/123456789) where pbxpeername is the asterisk
peer name for that client, and 123456789 is the extension I would like
to send the call to,  how would I do it in opensips? is there any
simple way, or do I have to manually find the registered ip address
and send the invite to there.

The calls are being routed through asterisk, so when sending a call to
a regular ip phone I send it as sip/phone at opensipsip, this works great
but I cant do sip/123456789 at phone@opensipsIP, so I will send a new
header with the extension and have opensips pull the header and
rewrite the to header, is there a simpler solution?