You'd have to use the NSH proxy, either by configuring the application server to act as one or by setting one up on another box. This will allow you (actually, I believe it will force you) to authenticate via username/password and role.
I don't know of an nsh command-line method for you to specify the role in which a command is executed on the remote host.
In RBAC you can change the default NSH role for a user, but that isn't what you're looking for and it's not a very scalable approach to have to go into RBAC and change that every time.
Chris Zappala <firstname.lastname@example.org>
Senior Consultant, Professional Services
That worked great! Thank you so much.
I'm glad that worked for you. (I'm assuming you configured an NSH proxy?)
Let me know if you have any other questions on that.