The problem remaining is you MUST "import" the file in C2 editor. You cannot tell a Player to drop files in this folder and expect them to load when the game runs :-/
Sadly a running C2 game has no way to reference a local file during runtime that wasn't imported during design/build time.
It does have "load image from url" and it has "filechooser" and there is the nwjs-object:
The NW.js object allows access to features specific to the NW.js exporter, such as reading and writing files to the local disk drive.
But I'm sure you have read The Manual extensively..
Like this part:
Previewing
Note that previewing with NW.js runs directly from its install directory. As a consequence, the AppFolder expression will return the install path. If this poses a problem for you, use the following workaround: have a global string variable; if 'Is in preview' is true hard-code it to some development folder somewhere else.