Restart remote PC via network by batch file and random timeout

How i can restart a remote PC on the same network and the same domain but i want to restart it with random timeout between 1 and 15 second by using batch file my command is :

Rem The below code it works properly and tested set /a "rand=(%RANDOM%*15/32768)+1" Rem The below code works properly without -t %rand% shutdown -r -t %rand% -f -m \xxxx how i can solve it and if any one can help me please write the correct code