How to Write Custom CSV File

Hi All!
I'm new to MP3Tag so probably just being dense.
I want to create a list of my songs. So, will be exporting to a CSV file and importing that to excel.
I use the itunes field called "grouping" to put codes in that allow me to make smart playlists.
I found that field in Mp3tag, it's called "contentgroup".
I can get the contentgroup field to display on the screen, but when I export to CSV, it is not included, even though it is being displayed on the screen.
I tried clicking on "edit" for the export configuration, but it wants to open an .mte file and I can't figure out how to open or edit it.
Is there an easier way to do this?
How do I edit the MTE file?
Thank you!
Kshemi

An export file is a plain text file that you can edit with a plain text editor like the Windows editor

Yes, but it doesn't include the information from the "contentgroup" field in it. How can I get that field to export with the other information?

you can add any field with the usual syntax like %contentgroup% or %my_very_personal_field%
You can also delete any field that you do not want for the export.

What you should take care of: the separator between the fields has to be unique. It must not be part of the data as otherwise it will cause havoc during import.

How do I edit the export? When I click on edit, it tries to open an .mte file. What program opens / reads that? Thanks!

see Post #2 How to Write Custom CSV File

A file carried on by Mp3tag, having the file extension MTE, is just a simple text file, which can be read, edit, write by any text editor, e.g. "notepad.exe".
If your computer system is not configured to have an "open with" property for the filetype MTE and a text editor, then you have to set up this property for yourself.
Do open the properties dialog of a MTE file (e. g. Mouse Secondary Click on the MTE file), ...
within the properties dialog find the text "Open with" ...
then use this further dialog to set up the binding between the filetype MTE and a text editor of your wish.

DD.20170623.1245.CEST

Thank you so much! I'm sorry I took so long to catch on!
This is thrilling!
I really appreciate your help!