LDAP authentication with internally managed access control?

I am working on setting up JasperReports Server 5.5.0 Community version for the first time. I would like to use LDAP for authentication, but want to manage access control within JS. The documentation describes how to map LDAP groups to JS roles, but I don't have (easy) access to define LDAP groups. I would like to give access to only a handful of users and give no access to everyone else. Can I do this without defining a group in LDAP and mapping it?