[Freeswitch-users] Looking up variable from config

Is there any way of looking up a variable from the XML config from the dialplan? For instance, I know what number is dialed from ${destination_number} and I know that the directory user entry attribute of ID matches the number because I have it set up that way. Can I lookup the value email-addr parameter from the user and, say, set a variable to the value? Something like an XPATH lookup?