I just put this together. Its a pretty simple bat file that seems to do the job. You may want try out on a select few computers in an OU to see if it produces the results you are after. Open notepad and paste this in and save the file with a .bat extension. Change the parameters to your liking. (ex. jsmith= name for the account you want to add; Cust0mPassw0rd= the actual password you want to assign to the account)
@ echo off
net user jsmith Cust0mPassw0rd /add
net localgroup Administrators jsmith /add
Push this out via Group Policy as a Startup Script.
Joey
A+, Network+, MCP