I have an LDAP server to which I do not have full privileges and an ubuntu system with LDAP authentication to which I am root. Is it possible to add an LDAP user to a local group? (I don't know if I phrase this correctly but all I want is to have a user in LDAP in a group without editing the actual database)
Based on your answer it seems like what you needed was:
$ addgroup <group_name> (to make the group)
$ adduser -g <groupname> <username> (to add the user to the group)