[Users] Access to pseudo variables from within core

[Brandon Price]

I have some questions about access to certain variables from within  
openser. The documentation states that I can access more of the  
pseudo variables like $fU and $fu from within more modules and the  
openser core. I am trying to use $hdr(From[0]) something that I can  
apparently still only do from within avpops or xlog. I need to have  
openser perform a certain action only if no SIP Display info exists  
if it does exist I do not want this action performed. For example....

             if ("$hdr(From[0])") =~ "^\<sip:.*") {....
do something
} else {
do something else...
};

Or if there is SIP Display info do A else do B. Any help greatly  
appreciated.