Add random number to batch file that generates temp passwords - batch-file

Question

I would be very grateful if some one could help me fix my script, I want to add a 4 digit random number to the end of a string, in essence it is a script that reads a csv file for an email address then creates a powershell file for me to run but the part im having issues with is the random 4 digit number appended to the password string, please see below, if I run the script now it runs without errors but no 4 digit random number appended, can anyone help im sure its something small im missing thanks
Spud
#echo off & setlocal EnableDelayedExpansion
for /F "delims=" %%j in ('type "Input.csv"') do (
set /A RND=%RANDOM% %% 8889 + 1111
echo.Set-MsolUser -UserPrincipalName %%j -StrongPasswordRequired $false
echo.Set-MsolUserPassword -userPrincipalName %%j -NewPassword "TTech%RND%*" -ForceChangePassword $false
echo.Set-MsolUser -UserPrincipalName %%j -PasswordNeverExpires $true
echo.
) >> "Output.txt"

Answer 1

You need to change %var% to !var! to access the dynamic value of a variable with delayedexpansion in effect.
set /A RND=!RANDOM! %% 8889 + 1111
would set your variable RND to 1111..9999
echo.Set-MsolUserPassword -userPrincipalName %%j -NewPassword "TTech!RND!*" -ForceChangePassword $false
would then append the resultant value to TTech
Alternatively, try
set RND=000!RANDOM!
...
echo.Set-MsolUserPassword -userPrincipalName %%j -NewPassword "TTech!RND:~-4!*" -ForceChangePassword $false
which would construct a string 000+0..32767 and then use the last 4 characters after TTech so you'd get leading-zero-filled 4-digit numerics.

Answer 2

Use this for your random number:
Set max=9999
Set min=1000
Set /A rand=%random% %% (max - min + 1)+ min
Echo %rand%
Keep in mind, inside of a for loop, you'll need to use delayedexpansion and escape the parenthesis.
Set max=9999
Set min=1000
for /l %%a in (1,1,10) do (
Set /A rand=!random! %% ^( max - min + 1 ^) + min
Echo.!rand!
)
exit /b
Based on Magoo's answer, you know the issue was with using delayed variable syntax instead of standard parens. I wrapped up his answer and mine into a couple of little functions that are easily reusable.
call :RandomRange 1000 9999 ret
Echo %ret%
call :RandomRange2 ret
echo %ret%
exit /b
:RandomRange min max ret
#echo off & setlocal enabledelayedexpansion
Set /A rand=!random! %% (%2 - %1 + 1) + %1
endlocal & set %3=%rand%
exit /b
:RandomRange2 ret
#echo off & setlocal enabledelayedexpansion
set rnd=000!random!
set rnd=!rnd:~-4!
endlocal & set %1=%rnd%
exit /b
Hope that helps

Answer 3

This will give you a random 4 digit number:
set num=%random%%random%%random%%random%
set num=%num:~-4%
Or with delayed expansion enabled inside a loop:
set num=!random!!random!!random!!random!
set num=!num:~-4!