Setting up Pure ftpd to run on certains port is very simple.
Log on to you linux box and run this command:

echo “60010 60030” > /etc/pure-ftpd/conf/PassivePortRange
/etc/init.d/pure-ftpd restart

or if you run mysql as a backend

/etc/init.d/pure-ftpd-mysql restart

Now you just need to forward port 60010 to 60030, to you linux box.