Create admin user from command line

[hiddenpremise]

As part of a project I am working on I need to be able to create an administrative user from command line. I can create a standard user just fine using the dscl tool, but for some reason I can't get that user in the admin group.

sudo dscl localhost -append /Groups/admin GroupMembership [I]adminshortname[/I]

As far as I know that should work, but I am getting

append: Invalid Path
<dscl_cmd> DS Error: -14009 (eDSUnknownNodeName)

When I try to run it. I am on a 10.5.4 MBP 2.16 Core Duo x 2G x 320G

Thanks in advance,
Whit

 

[hiddenpremise]

I figured it out... path needed to be /Local/Default/Groups/admin