Of course you can make the folder, where the shuffled files go, anywhere you like. See the line in red below.
@echo off
setlocal enabledelayedexpansion
set shuffledfolder=c:\some\folder\whatever
set stringlen=3
set case=UPPER
IF /i "%case%"=="UPPER" (
set minval=65
set maxval=90
)
IF /i "%case%"=="lower" (
set minval=97
set maxval=122
)
echo START PROCESSING FILES
for %%A in (*.mp3) do (
call :makestring
echo %%A ---^> %shuffledfolder%\!rstring!_%%A
copy "%%A" "%shuffledfolder%\!rstring!_%%A"
)
echo FINISHED PROCESSING FILES
pause
exit /b
:makestring
set "rstring="
set chars=0
:genloop
set /a "ascii=%RANDOM% * (%maxval% - %minval% + 1) / 32768 + %minval%"
cmd /c exit /b %ascii%
set letter=%=ExitCodeAscii%
set rstring=%rstring%%letter%
set /a chars+=1
if %chars% LSS %stringlen% goto genloop
goto :eof