[Freeswitch-users] Strip and use SIP headers in freeswitch dialplan configuration

Hi All, Am trying to fetch "Proxy-Authorization" header present in the SIP INVITE request through dialplan xml. Since there is no Built-in variable to fetch this header, is there a way to find if this header is present in the SIP INVITE request?. I browsed to find any possible solution but wasnt successful. Thanks, Vivek