Hi Kevin,
Wow, you want to connect the game engine to HANA 
Can you write a blog post about your success?
Regarding your question, I do not know how to do exactly what you want. But, you can try to deploy the XML file to any XS folder and then configure your web dispatcher (or proxy server) to change interpret the XML link as if it is placed into the root.
By the way, I think it is insecure to use the direct connection from the application to HANA without a proxy or web dispatcher. So, sooner or later you have to install proxy.
Kind regards,
Vlad