You want the comment of "all" tracks to be tagged with appended comments from any other comment field in selection (no main)?

See here

If Comment is the only one involved and case of 1+2+3+x needs to be result on all tracks then It should be very easy to make script and button to do that on selected tracks.

You mean, for example,

1. You have 5 tracks in a project, you designate one track as the main one with the "comment" field as the target.
2. You then proceed to append the "comment" of the other 4 to the "comment" of the main track?

The only thing I can think of would involve using 2 add-ons (1 and 3 in my signature under fav scripts).

1. Use add-on #3 first to copy the "comment" of each of the 4 tracks separately to unused capable fields of the main track.
2. Use add-on #1 to append each of the 4 "comment" to the "comment" of the main track.

I was wondering whether there was a script or Add-on that would concatenate existing tags for multiple tracks such that:
Tracks starting with :
Track 1 Comment: String1
Track 2 Comment: String2
Track 3 Comment: String3

Could be tagged as
Track 1 Comment: String1String2String3
Track 2 Comment: String1String2String3
Track 3 Comment: String1String2String3

Sorry if this question already exists or isn't clear. I'm new to the forum.
Thanks in advance for anybody who can point me in the right direction.