Watch this video to see how easy it is to make mass changes to Active Directory from an external text file without using complicated scripts.
moveuser <user1> <user2> [/y] [/c:computer] [/k] Description: moveuser.exe changes the security of a profile from one user to another. This allows the account domain to change, and/or the user name to change. Arguments: user1 Specifies a user who has a local profile. user2 Specifies the user who will own user1's profile. This account must exist. /y Allow overwrite of existing profile. /c Specifies the computer to make the changes to. /k Specifies if user1 is a local user, then the user account should be kept. Specify domain users in DOMAIN\USER format. Specify only USER for local accounts.