for me regular expressions are much easier to understand and use than the current [tags] while using the multi-rename tool.
I can't think of any reason on what type of rename operations where I can use the tags currently available with it.
I would too love to see regular expression support since I too rename very much mp3 files.
I even would like to suggest a savelist for multiple regexp to make it a bit easier if you only know the basics.
for example I have the following directories:
Adam_Beyer_and_Henrik_B-Year_Of_Reflection-Vinyl-2002-UTE
Alicia_Keys-Girlfriend_(KrucialKeys_Video_Version)-2002-BLEH
Anouk-Graduated_Fool-CD-2002-3G
Tenacious_D-Tribute-CDS-2003-3G
I would like to rename them all to:
Adam Beyer and Henrik B - Year Of Reflection vinyl (2002)
Alicia Keys - Girlfriend (KrucialKeys Video Version) (2002)
Anouk - Graduated Fool (2002)
Tenacious D - Tribute single (2003)
so I would have a savelist of regexp that would look like this and goes through from 1 till the end:
1. replace ^(.*)-(.*)-(.*)-([0-9]{4})-.* with $1 - $2 $3 ($4)
2. replace ^(.*)-(.*)-([0-9]{4})-.* with $1 - $2 ($3)
3. replace Vinyl with vinyl
4. replace CD with <empty string>
5. replace CDS with single
6. replace / +/ with / / (multiple spaces with only 1 space)
Very nice would even be that I can select which regexp numbers I want to use that session.
Reason I ask is that currently I have about 300 lines of regexps writting in a php script. I do under dos prompt a "dir /b >dirlist.txt", enter the contents in a sendform and let it go through my php script that outputs the contents for a msdos batch file that renames it how I want it renamed.

it works like a charm... hehe
but if it could be done from within tc... man! It would rock!