basically it says
for every user 9 months inactive, disable the user with dsmod command
pipe the list of "dsquery user -inactive 9" to "dsmod user -disabled yes"
so a couple things.
if its 2003 specific, and dont have 2003 you may be out of luck
if you do, then you need to install your resource disks
we do have server 2003... i'll look for those disks i guess
you have the commands, its just the way your executing is wrong or something is wrong
try to execute one command at a time