But I have files like...
D:\Mű\Zene\Régi őrző\ Чайко́вский\Évszakok. Vihar [OroszÁll.ÖHkar vez.Светла́нов]\Vihar, zenekari ábránd\01. Vihar (f-lágy zenekari ábránd Shakespeare színműve után).flac
...and the tool does not work, because of cyrillic letters. My OS is Win7 hungarian.
Is there a solution? Workaround exists: Total Commander x64 open all files without problem -- but some time is more comfortable to use the windows explorer.
I am not sure if this has something to do with the character set that you have in the tags and that what the OS uses.
So if you have ISO-encoding in the tags, it may be worthwhile to try to convert them to UTF encoding or vice versa.
It seems, the behavior is associated not with the tags, but the path. Removing all tags changes nothing.
From Mp3tag I can not it send to windows explorer -- explorer allways opens C:\Users\MyName folder. For the same these (and any) files from foobar, using Florian's foo_run, I can open their folders without any problem. And opening the file, or its folder from Mp3tag works for Total Commander, IrfanView, Spek, foobar, Firefox -- only Explorer does not.
But I noticed: problematic are not cyrillic letters themselves, but cyrillic letters with accents.
D:\Mű\Zene\Régi őrző\ Чайко́вский\Évszakok. Vihar [OroszÁll.ÖHkar vez.Светла́нов]\ ...
...does not work, while...
D:\Mű\Zene\Régi őrző\ Чайковский\Évszakok. Vihar [OroszÁll.ÖHkar vez.Светланов]\ ...
...does.
This accent on cyrillic letters is a separate character after the vowel: CC 81, $char(769).
$replace(%_path%,$char(769),) does not work, as I expected.
Try this tool:
Name: Select File In Explorer
Path: C:\Windows\System32\cmd.exe
Parameter: /c FOR %%A IN ("%_path%") DO Explorer.exe /e,/select,%%~sA
Ryerman, thank you for try. Sorry, it opens C:\Users\MyName folder, too.
OK, thanks for testing. 
It requires that 8dot3 names have been created in the target file's directory.
But that may not be true in your case.
Please open the command prompt, issue this command: "fsutil 8dot3name query D:" (without quotes), and tell me the results.
Maybe you will see a message like "The volume state is: 0 (8dot3 name creation is enabled)."
See here: fsutil 8dot3name | Microsoft Learn
and
Welcome thinkplexx.com - BlueHost.com
Thank you, again, but creating new files for simply opening the folder for me is not worth. Easier is to open Total Commander.
OK, but my suggestion has nothing to do with creating new files.
And just to be clear, the tool does not create new files.
The tool uses 8dot3 file names that have already been created by the Windows operating system.
They are available for use as file specifications instead of the long file names you see in File Explorer.
Oh! Understood. I try it in the nearest days.
The task is solved for me. The only reason, I sometimes wanted to use Win Explorer, was my lack of knowledge. The tool always opened a new TC window -- to work in it, instead of the previously set one, and to lock it after, is very uncomfortable. However, now I found the appropriate switch for TC: "C:\Program Files\totalcmd\TotalCmd64.exe" /O /T "%_path%". It opens a new tab at the end on the active side of the existing TC process. At the end of my work I double-click on this tab to close -- and that is all.
From that point on, fortunately, we can forget about the billgates patchwork.