First, sorry, I got that MC Global shortcut wrong in my last post. It should have been;
<Entry Key="Shift;F4"
Type="Program" Command="C:\Program File (x86)\Dreamscreen\Dreamscreen_Ambient_Modus.bat" Global="1" />
I did some testing and this shortcut works as long as MC is running, whether it is in Standard View, Theatre View, the in-focus application or not.
But I figured that you would want this shortcut to work even if MC wasn't running. So I added a Windows shortcut for the same key combination, and the shortcut then worked when MC was not running. It also worked when MC was in Standard View and in-focus or not, or in Theatre View but not in-focus, but it didn't work if Theatre View was in focus.
So I changed the MC Shortcut so that it was no longer Global, expecting that when MC was in-focus the MC shortcut would always be used, so Theatre View would work, and otherwise the Windows shortcut would be used. Same problem, nothing happened in Theatre View.
So I added a Translate Flag so that the MC shortcut would only be active in Fullscreen, expecting that to mean Theatre View. (Note that I was actually testing using the Ctrl+Shift+F4 key combination, and a program called Notepad++.)
<Entry Key="Ctrl;Shift;F4" Type="Program" Command="C:\Program Files (x86)\Notepad++\notepad++.exe" TranslateFlags="8" />
That still didn't work in Theatre View. In fact, it didn't even work when I deleted the Windows shortcut. Maybe fullscreen doesn't actually include Theatre View.
So my conclusion is that having a Windows shortcut defined using the same key combination as a shortcut in MC using resource.xml just will not work with Theatre View in-focus. If MC is always going to be running when you want to use this shortcut, then the above setting will work.
However, I see a potential problem in that solution;
I corrected a mistake in my initial post, the key stroke is "Ctrl"+"F4".
Ctrl+F4 is a standard Windows General shortcut key combination. It means "Close the active document", which for example in Chrome will close the current tab. See
https://support.microsoft.com/en-us/help/12445I thought you did well when you had picked Shift+F4 as the combination because it isn't assigned as a Windows Shortcut as far as I can tell. Plus it is a nice simple shortcut. It is used in quite a lot of applications though, as application specific shortcuts:
https://defkey.com/what-means/shift-f4 I assume that when you defined the Ctrl+F4 shortcut you were overriding the standard Windows default.
If you use Ctrl+F4, that will override the Windows shortcut. For example, with MC running and the MC Global Ctrl+F4 shortcut in place, Ctrl+F4 no longer closes the current tab in Chrome, but runs the defined program instead. So Ctrl+F4 would have two different actions in Chrome, depending on whether MC is running in the background.
I suggest that you don't use Ctrl+F4, or even Shift+F4. Use a MC Global shortcut of Ctrl+Shift+F4 instead, although even that key combination is used in some applications, so if you have one of those applications open and in focus it is likely to override your MC Global Shortcut. See
https://defkey.com/search?irq=Ctrl+Shift+F4.
I think the below is your best solution, and only expect it to work when MC is running. Delete the Windows key combination you have assigned to the batch file shortcut.
<Entry Key="Ctrl;Shift;F4" Type="Program" Command="C:\Program File (x86)\Dreamscreen\Dreamscreen_Ambient_Modus.bat" Global="1" />PS: The Core Command "20000" for "MCC_OPEN_FILE" doesn't take any parameters. Any supplied parameters are ignored, as per the Core Commands Wiki:
https://wiki.jriver.com/index.php/Media_Center_Core_Commands