freeswitch failover on certain termination causes

Hi I have a quite straightforward freeswitch configuration and I'm currently using freeswitch's failover feature with the directive: <action application="transfer" data="cfailover1"/> ... it works decently but I'd like to be able to failover (to the next trunk) only on a given list of 'dispositions' and/or 'hangup causes' to be more clean, i'd like to discriminate based on the following variables: ${originate_disposition} ${endpoint_disposition} ${hangup_cause} ${last_bridge_hangup_cause} ${bridge_hangup_cause} please contact me if you are a freeswitch billing expert and consider that I'm open mind about your suggestions since I'm probably missing something with all those termination causes :)