How to add new files to portable app ?

like the topic,

I have build portable app using thinapp..

but I have a need to add new files into the portable app with ease (as it have to be done by the user that only have little knowledge about IT/computer).

is there anyway to do this without re-build the portable app and do it with ease ??

ps : I know how to update the existing files with ease, but I need to add new files with ease (like just copy the new files to some folders), and not using the built-in cmd (because it would be too much to teach the users to use cmd)

thx