[Freeswitch-users] Access to users variables

Hi! How can I access the variables that are defined in a users xml file? For example, say user 1000 has a variable called smsnumber, as defined below: <include> <user id="1000" mailbox="1000"> <params> <param name="password" value="1000"/> </params> <variables> <variable name="smsnumber" value="12345"/> </variables> </user> </include> How can I use variable ${smsnumber} in a dialplan to run a perl script using <action application="system" data="sms.pl"/> ? Thanks