I can give you an example...
'\\NETLAGER\F\NAS\Foto\Knuth\2019\04April\2019 04 24\20190424_171636.jpg'
They are all pictures, and they are all named yyymmdd_hhmmss.jpg - all numers adn underline - with ext jpg
Some are found, and some are not.
Been running this test a couple of times now.
All files already exist (according to Windows Explorer).
If the file is not found, it is copied.
And it seems, the next time, it will find the files, the program has created itself - even if there is no difference in filename.
(Copying overwrites existing files - on purpose)