from perl i'm connecting to FS using FS' ESL library and issuing an originate command which fails when i try to use ${distributor()}

It seems FS' ESL Library or perl itself is changing "$" for "%", i get an error:

2014-09-07 20:25:57.484946 [ERR] mod_sofia.c:4249 Invalid Gateway '%{distributor(mylist)}'

The command is actually:

my $uuid = $con->bgapi("originate", "sofia/gateway/\${distributor(mylist)}/$destination &callcenter(myqueue)"); 

So i'm scaping $

Has anyone experienced this?

Thanks for you help!

David