Using Sencha CMD to concatenate/minify existing ExtJS Application

I have an existing ExtJS MVC application built by hand (e.g. NOT using CMD or other tools) and I want to use CMD to concatenate all the files into a single JS file but can't seem to find the proper command structure to do it without getting the "Command must be run from an application folder" error.



Do I need to generate an app using CMD then move all my JS code over to the appropriate folders to make this work?



Thanks