call_id sip_user sip_host presence_hosts contact status rpid expires user_agent server_user server_host profile_name hostname network_ip network_port sip_username sip_realm mwi_user mwi_host orig_server_host orig_hostname 

fields, so how can I get these vars from the callee before the bridge ?

I need to replace the host of the callee in case of if he's registered on another FS node.