Seems Square online is basically setup for non-programmers - the UI and Editor are fairly easy however, when it comes to tweaking any code, it's a challenge. If you're used to doing your own coding and using FTP to up load your files to a server, then what you have in mind is simple however, with Square's setup it's not. Many hosting services offer an App called cPanel which has a graphical and intuitive interface that provides all of the tools you need to manage software, websites, email, databases, and more. And if you work locally like I do, I can FTP my files to the Server - neither of these options are available from Square (at least that's what I'm aware of). You may want to check with the Developer Forum as those folks may have some suggestions to help you out.
