You should be able to create local groups on the server and then link to those groups within the web console.
From the Admin Guide (p228):
"complete the following steps:
- Provide the User Name and Password for a user that has administrative access to your Active Directory or local domain.
- In the Search for Account area, enter the Group name of the Active Directory or local domain group for which you want to create a new web console account, and then click Search.
- In the Add Users area, select the users for whom you want to create new web console accounts, and then click Next.
- User Account view displays, showing all configurable account options. For more information about editing account settings, see "Editing User Accounts" on page 228."