Why are my DLLs not found despite me importing the path? And can I use VLC in python without installation?

Question

I have written a small program that generates a system tray icon that can play radio streams from a handfull of stations. It is running well for a year now and I tried to update the code and also the instructions of how to compile it with pyinstaller. My goal is to make it generally very easy to use.

While doing so I set up a new development environment with PyCharm with python 3.9 as interpreter. I encountered some problems. Which is actually good, because I wanted to replicate the process of compiling it from scratch.

Using pip, I installed pywin32 and python-vlc in the venv.

I also installed a 64bit version of vlc in C:\Program Files\VLC Plus Player (which seems to be the new standard path).

Now I have two problems. The dll path is not found despite my effort to import it with add_dll_directory. I did not have to do this when I originally wrote the program with an earlier version of Python. (Maybe I set the PATH in Windows.) I would like to rewrite the program now so that no further changes have to be made.

Also, I would like to make the program standalone, removing the need for an installation of VLC for the user. There is a 14 year old thread which indicates that it maybe could be possible to include VLC itelf. Any comments if this might be possible are very welcome!

So far I tried to just putting the dll's into my working directory. This will remove the first problem. But then self.vlc = vlcimp.Instance() will return None, probably because there is no real VLC that can return something.

import sys
import win32ui
import os

os.add_dll_directory(r'C:\Program Files\VLC Plus Player')
import vlc as vlcimp

import win32api
import win32con
import win32gui_struct
import threading
import webbrowser

try:
    import winxpgui as win32gui
except ImportError:
    import win32gui

class SysTrayIcon(object):
    QUIT = 'QUIT'
    STOP = 'STOP'
    SPECIAL_ACTIONS = [STOP, QUIT]
    FIRST_ID = 1023
    def __init__(self,
                 icon,
                 hover_text,
                 menu_options,
                 menu_options2,
                 on_quit=None,
                 default_menu_index=None,
                 window_class_name=None,):

        self.button_doubleclicked = False
        self.playing = None
        self.playingID = ''
        self.toggle = False
        self.vlc = vlcimp.Instance()
        self.player = self.vlc.media_player_new()
        self.icon = icon
        self.hover_text = hover_text
        self.on_quit = on_quit
        self.menu = None

The exception when no dll is found is:

Traceback (most recent call last):
  File "C:\Users\....py", line 22, in <module>
    import vlc as vlcimp
  File "C:\Users\...\venv\lib\site-packages\vlc.py", line 210, in <module>
    dll, plugin_path  = find_lib()
  File "C:\Users\...\venv\lib\site-packages\vlc.py", line 170, in find_lib
    dll = ctypes.CDLL('.\\' + libname)
  File "C:\Users\...\AppData\Local\Programs\Python\Python39\lib\ctypes\__init__.py", line 374, in __init__
    self._handle = _dlopen(self._name, mode)
FileNotFoundError: Could not find module 'C:\Users\...WORKING_DIRECTORY\libvlc.dll' (or one of its dependencies). Try using the full path with constructor syntax.

Process finished with exit code 1