How to Copy user and create in different Domain with workflow[ or policy.

Our ARS manages both Dev and Prod. We get requests for users to be created in Dev domain which has to have the same FirstName,LastName,SamAccountName and a few other attributes as PROD. How would I create a process for Admins to search the Prod user name in the ARS Website, select it and have a form button that they can click "Create in DEV". Workflow triggered of a attribute change or Policy..? Any ideas to approach would be appreciated especially if you have done similar.