[Help]Asus RT-N66U advanced configuration

[Cigaras]

I have Asus RT-N66U with Merlins firmware and there is a service there Udpxy running with predefined parameters that do not satisfy me and I need to change them, so I connect to the router through Putty, and do following commands:

killall udpxy
udpxy -m eth0 -p 4000
iptables -I INPUT -p tcp –dport 4000 -j ACCEPT

And everything works as I like it, but after rebooting Router loads it's default settings for Udpxy and for the open port, how can I change the default settings if they are not available in GUI?

P.S. Sorry for my bad English.