Setting the chanel to listen to...

I ame useing the script that allows me to change the URL of the station I am streaming on my land:

//This simple script will listen for the owner to say radio: URL
//it will tune to the station specified by the radio: command.
default
{
state_entry()
{
llListen(0,"",llGetOwner(),"";
}
listen(integer channel,string name,key id,string msg)
{
string lmsg=llToLower(msg);
if("radio: "==llGetSubString(lmsg,0,6))
{
llSetParcelMusicURL(llGetSubString(msg,7,-1));
}
}
}

I would like to use a nonvisable chanel so I am not spaming URL to everyone. Also woudl it be posible to creat a list of urls and asign a name to them this way one could use the privat chanel and say /123 radio: Goth and the script woudl tune the URL tied to the name "goth"?

thanks for the help

//This simple script will listen for the owner to say radio: URL
//it will tune to the station specified by the radio: command.
default
{
     state_entry()
     {
          llListen(0,"",llGetOwner(),"");
     }
     listen(integer channel,string name,key id,string msg)
     {
          string lmsg=llToLower(msg);
          if("radio: "==llGetSubString(lmsg,0,6))
          {
               llSetParcelMusicURL(llGetSubString(msg,7,-1));
          }
     }
}

The value in red is the one you need to change.