@echo off
setlocal EnableDelayedExpansion

set "name=myname"
set /a usr_num=1

set "alp=@ # ^& % a A b B c C d D E e f F g G h H I I j J k K l L m M n N p P q Q r R s S t T u U v V w W x X y Y z Z 0 1 2 3 4 5 6 7 8 9"
set "cnt=0" 

for %%a in (%alp%) do (
  set "rn.!cnt!=%%a"
  set /a "cnt+=1"
)

(
  echo Username,Password
) > users.csv

:userloop
if !usr_num! lss 10 (
  set "username=%name%.usr!usr_num!"
  
  set "pssw="
  for /l %%a in (1,1,13) do (
    set /a "rand=!random! %% cnt"
    for %%b in (!rand!) do set "pssw=!pssw!!rn.%%b!"
  )

  net user !username! !pssw! /add /passwordchg:no /expires:never

  (
    echo !username!,!pssw!
  ) >> users.csv

  set /a usr_num+=1
  goto :userloop
)

endlocal