How can I use variables in rest proxy URL?

Hi

Am am building touch apps and use my local server to test it but when I want to package it as a native app I have to update all urls in the app.js to point to production url.

url in proxy is defiend as a string and I can not use a vaiable in it wich otherwise had been an easy way of switching between local and remote url for testing.

I am considering writing a small code that updates all url during application lounch process, but you might have better solutions for this.

How can I use variables in rest proxy URL?