Hi,
I think something like this may do want you require and it is not skin dependent.
http://forum.kodi.tv/showthread.php?tid=69797
you need to change the path in the script, to path of your usb drive so:
path="E:\\videos"
needs to change to something like:
path=/Media/<label of USB drive>
Also you need to save the desscribed script as, Autoexec.py
http://kodi.wiki/view/Autoexec.py
Thanks Tom.