adding a letter in front of the title/track name

my eac rips the tracks as 01 - trackname.flac
I want to use mp3tag to auto tag a selected group of files as 01 - a trackname.flac

how can I set this up to do it automatically, using the alphabet a,b,c
example:
01 - a trackname
02 - b trackname
03 - c trackname
and to include the space between the a(letter) and trackname

Which alphabet do you want to apply?
See also ...
https://en.wikipedia.org/wiki/Alphabet
https://de.wikipedia.org/wiki/Alphabet
https://de.wikipedia.org/wiki/American_Stan...ion_Interchange
https://en.wikipedia.org/wiki/ASCII

These formulas work for the range 'A'..'Z', for TRACK=1..26
$char($add(64,%TRACK%))
... or ...
$char($add(64,%_counter%))
... or ...
$mid('ABCDEFGHIJKLMNOPQRSTUVWXYZ',%TRACK%)

These formulas work for the range 'a'..'z', for TRACK=1..26
$char($add(96,%TRACK%))
... or ...
$char($add(96,%_counter%))
... or ...
$mid('abcdefghijklmnopqrstuvwxyz',%TRACK%)

You may apply the Mp3tag Convert dialog "Filename - Filename" ...
Old filename Pattern: %1 - %2
New filename pattern: %1 - $mid('abcdefghijklmnopqrstuvwxyz',%1) %2

Please explain for which practical use it is worth?

DD.20150729.0745.CEST

I cannot imagine what the purpose could be ... please enlighten me.

Use the function Convert>Filename-Filename
Enter as Source: %1 - %2
Enter as Target: %1 - $char($add(64,%1)) %2

This takes the leading number and transforms it into a letter.

For some strange reason my car stereo does not use number tag when playing the audio track, instead the player will sort by alphabet a - z and rearranges the files as such.

Youtube video

this is what i want to do. can this action be set up in a repeatable scrip?