I don't know if that's really possible, checkout Loader.js getPath method:
Code:
getPath: function(className) {
var path = '',
paths = Loader.config.paths,
prefix = Loader.getPrefix(className);
if (prefix.length > 0) {
if (prefix === className) {
return paths[prefix];
}
path = paths[prefix];
className = className.substring(prefix.length + 1);
}
if (path.length > 0) {
path += '/';
}
return path.replace(slashDotSlashRe, '/') + className.replace(dotRe, "/") + '.js';
},
where dotRe = /\./g
So as a small example I tried this:"Ext.a.b.c.d".replace(/\./g, "/") + '.js';
And returned"Ext/a/b/c/d.js"
You could try to override this method so the return does not replace the className...
Good luck