Run a TOOL Command, based on selection, in a SINGLE WINDOW

Apologies, sir, for the late response. Nevertheless, your VBS Script, for FFmpeg, worked, in which, once again, I am very grateful. As for using your name as a format string, %ryerman_mte%, it's more to establish the VBS Script author. I believe this is the 3rd VBS Script that you wrote for me, and, in the 3rd one, it provided a more detailed message box regarding total number of files and commands processed, which I incorporated into your second VBS Script, my favorite one: mkvpropedit (%mp3propedit% as the format string). Believe it or not, your second VBS script has done more wonders than you could have imagined because I created .MTEs' of the script for Exiftool, WinTestGear's FileTouch v1.0.0.3, and NirSofer's Property System View. The only issue that I have with NirSofer's Property System View is that if an Mp3Tag FIELD contains double quotations, NirSofer's Property System View will only write into the Mp4 properties up to the first double quote, deleting everything else. I searched online on how to escape it as you would do for regex, but no luck.

As for your question regarding the multiple file extensions, which correlates with all the file extensions MP3Tag can read (excluding .mks), it was for WinTestGear's FileTouch v1.0.0.3 .MTE file to change the dates for various media types, and since ffmpeg can read practically almost every media, I thought it would be appropriate to use it as well. Nonetheless, thank you, once again, because you solved my MP4 problem regarding Windows Explorer File Properties, in which I used your 2nd VBS Script Template responding to someone else's post: RESPONSE to incorporate NirSofer's Property System View with Mp3Tag's .MTE file

Moreover, there is no way I could have figured it out for ffmpeg in LINE 30 of the VBS Script. Therefore, I was wondering if you could direct me to what guides (i.e. books, forums, et cetera) you used to learn how to write VBS Scripts because you are correct about the command arguments in LINE 30 being tricky, especially when to use single/double quotations as the last argument before the next & chr(34). For example, "'%ryerman_mte%"' vs "'%ryerman_mte%'", in which the first %ryerman_mte% is ended by a SINGLE quote, and the second %ryerman_mte% is ended by a DOUBLE quotation, as well as every line must end with an even-number of SINGLE quotes.

Lastly, thanks because, though I am not an expert like you nor DetlevD, whom, apparently, has been dubbed the father of .MTE files, I can comfortably write my own regex, given the .MTA file you wrote for me to convert format of date and time from, for example, 6/25/2022 11:25:33 PM to 2022-06-25 23:25:33. Thank you, again, sir, for your help and patience. I really appreciate it.

You are using ryerman_mte as the name of a field you have created to hold some information.

The name of a user created field is unimportant.
But nobody can read your mind with respect to how you populate a non-standard field.
When you're asking for help with a command line it is necessary to provide details of the data that it may contain.
A fully expanded, complete example of the command line is usually helpful.

If you always exported only files that are allowed by the external application, no check of file extensions is required.
Checking file extensions in these scripts assumes that you might export files that you do not want to process.
In other words, you can select all files without sorting beforehand and let a script process only the desired file types.
If a particular command line accepts any and all of the files that you allow to be loaded into Mp3tag, there is no reason to check file extensions.
Some applications (like mkvpropedit) expect certain file type(s).

In VBS, single quotes are used to signify comments: anything after a single quote is ignored at execution.
If a single quote is required for a file specification on a command line or anywhere not enclosed in double quotes, I use chr(39) instead.
In Mp3tag, single quotes are used to escape special characters.
In an export script, anything surrounded by single quotes is treated literally.
So single quotes surround the VBS statements/commands when using the export function to write a VBS script.
In your example of "'%ryerman_mte%'", the single quotes are not surrounding %ryerman_mte%.
If you examine the MTE script carefully, you will see that the first single quote is the trailing quote of the quotes surrounding the preceding part of the command.
And the second single quote is the opening quote of the quotes surrounding the following part of the command.

It is tricky because we must obey the syntax for VBS scripts while writing the VBS script using the syntax of MP3tag export scripts, all the while fullfilling the requirements of a particular command line.
I can't think of a foolproof rule that governs every case of when to use " or chr(34) or ' or chr(39).
That is why it is important to give a good example of the command line and to give details of the data that will be exported.
My usual procedure is:

  1. Compose a command line that works in the command processor.
  2. Create a VBS script that properly executes the command line.
  3. Create a MTE export script that writes the VBS script and adds the desired file data. That usually means looping through the file paths.

I didn't learn VBS scripting in any formal setting or online.
I did learn FORTRAN and BASIC, way back when I was young, so I am familiar with programming.
When I started using VBS, I was a "copy and paste" programmer: I would search online for a specific task and use whatever code I found.
I slowly learned some of the basics but I have little in-depth knowledge.
If you google "Learn VBS", you will find some information about online instruction.