I don't know if any plugin offers such functionality, I sort of like remember that there was something to save variables, but couldn't find it. So I did this plugin in 15 minutes to save xlobby variables. I was getting tired of having to set couple of things everytime xlobby started
So there you have it... if anyone finds it useful. Extremely simple plugin, it only knows to 1) save xlobby variable to registry 2) read from registry to xlobby variable
documentation: http://xlobby.lanik.org/XPreferences.htm
download: http://xlobby.lanik.org/XPreferences.v0.01a.exe (installer)