We have developed a custom method by which a User, with the correct rights, can change the password on a User from within a Workflow. What makes this important is that the password change is integrated with a custom Java class which calls NMAS methods to do the password change. The password change is thus verified and, on an error, a task is reassigned to the requester with the NMAS error. The process is retried until the password is successfully set.
The code is now available on GitHub here