Here is real simple script to use to create bulk AD users for your test environment. When you execute the script it will ask you simple questions, all you need to do it to type input based on your scenario, script will take your input and execute within the shell. and at the end it will list the users which have been created.
I wrote this script please fell free to change or add anything you like.
Download the script from here
After downloading the script execute it
Script will ask you three questions
After you specify how many users you like to create ( you can create as many users as you like)
Script will show you the users, you will also find these users on the default user contained within ADUC.
Easy enough (-: , Enjoy it