UDI Add Local Administrator and Change Local Administrator Username

Question

I'm unable to find any information on how to either add a new local user admin account, or change the default local user admin account name during SCCM 2012 SP1 UDI OSD. The AdminAccountPage only has two areas, Local Administrator Password Text Box, and
Administrator User Accounts Text Box. 
The first one, Local Administrator Password Text Box, works when I set a variable that corresponds to a password for the default local user admin named "Administrator". We'd like to change the name of this default local user admin to something
else, like "Help Desk". 
The second area, Administrator User Accounts Text Box, lets me add users to the computer local administrators. We're fine adding domain users, but I'm not understanding how local users get added. Would the local user have to already exist in the reference
image? I see that the OSDAddAdmin variable will take either domain\user or computer\user. If I put in computer\user, and it's an account that doesn't already exist on the reference image, does it create a new local user account? And if so, how do you set a
password for this account?
I'd appreciate any help or advice anyone can give me. Thanks. 

Answer 1

Is using Group Policy available to you? This would be a far easier way to add additional local accounts to your computers, rather than trying to modify the default built in local administrator account.
As an example: http://www.techrepublic.com/blog/the-enterprise-cloud/deploy-local-accounts-via-group-policy/
You would be able to provision new local accounts i.e. HelpDesk outside of Configuration Manager.
Regards
Damon