As noted by ak, exactly the same thing can be done using a bat.
I have just figured how to make such bat, so that the tags are written correctly. It's a little bit bigger than ak's one

So here it is:
bat file for EAC.
Tested it on win2k, seems to work.
It must make one "main" encoding - the one that EAC would think it encodes. And any number of additional encodings. It is also possible to change the output directory for these extra encodings to avoid overwriting (when encoding to the same format, different quality).
EAC settings:
User-defined encoder
.mpc
C:\WINNT\SYSTEM32\CMD.EXE
command line: /Q /C eac_userdef.bat "%a" "%g" "%n" "%t" "%y" "%m" %s %o
CODE
echo 1 (artist)=%1
echo 2 (album)=%2
echo 3 (track)=%3
echo 4 (title)=%4
echo 5 (year)=%5
echo 6 (genre)=%6
echo 7 (input)=%7
echo 8 (origin)=%8
echo .
set drive=%~d7
set dir=%~p7
set name=%~n7
set origin=%~n8
rem ..................We assume that input, output and origin are all in the same directory.
rem ..................Change current drive and dir.
%drive%
cd %drive%%dir%
set mpc_tags=--artist %1 --album %2 --track %3 --title %4 --year %5 --genre %6
set lame_tags=--add-id3v2 --pad-id3v2 --ta %1 --tl %2 --tn %3 --tt %4 --ty %5 --tg %6
set vorbis_tags=..........
set mp4_tags=???....
rem .......................................................................
rem ............ the first (default) encoding -- using EAC-generated input file name
rem ............ (output file extention must be the same as specified in EAC compression options)
rem .......................................................................
rem ....................................................................MPC-1
set comment_tag=--comment "ripped by XYZ, mppenc v1.15r, --standard"
mppenc.exe %mpc_tags% %comment_tag% --standard --xlevel "%name%.wav" "%name%.mpc"
rem .......................................................................
rem ............ Any additional encodings -- using origin name for output,
rem ............ and we can also place the files in any directory
rem ............ (don't forget to change extention, e.g. ".tmp", if necessary)
rem .......................................................................
rem ....................................................................LAME-1
set comment_tag=--tc "ripped by XYZ, lame 3.90.2, --alt-preset standard"
lame.exe %lame_tags% %comment_tag% --alt-preset standard "%name%.wav" "%origin%.mp3"
rem ....................................................................LAME-2
set comment_tag=--tc "ripped by XYZ, lame 3.90.2, --alt-preset 135"
lame.exe %lame_tags% %comment_tag% --alt-preset 135 "%name%.wav" "%name%.tmp"
set outdir=lame_128
if not exist "%outdir%" mkdir "%outdir%"
move "%name%.tmp" "%outdir%\%origin%.mp3"
:end
Edit: I think we can throw away the %d, to avoid the possible "too long command line" bug.
Changed the bat accordingly.