In order to generate of users for your customer's needs, you may run the DS* set of tools that are included with the administrative tools for Windows 2003 and 2008. These built-in command line tools can grab user content based on the criteria you pass to the command. The following examples below are a few useful ones that can be redirected into a text file for viewing:

Get a User List for a Particular Customer

dsquery user -limit 1000 | dsget user -fn -ln -display -desc -pwdneverexpires -acctexpires -disabled

Get a User List of Inactive Users for a Particular Customer (Over 13 Weeks of Inactivity)

dsquery user -inactive 13 -limit 1000 | dsget user -fn -ln -display -desc -pwdneverexpires -acctexpires -disabled

Get a User List of Users Who Haven't Changed Their Passwords for a Particular Customer (Over 45 days)

dsquery user -stalepwd 45 -limit 1000 | dsget user -fn -ln -display -desc -pwdneverexpires -acctexpires -disabled

There are many more combinations that you can pull out from Active Directory. You just need to review the list by running the DS* command with a /? for the additional options.