How comfortable are you with openldap ACLs?
I'm doing the same thing to delegate access to techs to administer their own container in open directory. These acls are stored in openldap itself under olcDatabase={1}bdb,cn=config. Here's a sample ldif:
version: 1
# LDIF Export for: olcDatabase={1}bdb,cn=config
# Generated by phpLDAPadmin (
http://phpldapadmin.sourceforge.net/ ) on February 3, 2009 2:04 pm
# Server: (my.opendir.com)
# Search Scope: base
# Search Filter: (objectClass=*)
# Total Entries: 1
dn: olcDatabase={1}bdb,cn=config
objectClass: olcDatabaseConfig
objectClass: olcBdbConfig
olcDatabase: {1}bdb
olcSuffix: dc=my,dc=domain,dc=com
olcAccess: {0}to dn.subtree="ou=somecontainer,dc=my,dc=domain,dc=com" by dn="u
id=someuser,cn=users,dc=my,dc=domain,dc=ca" write by dn="uid=diradmin,c
n=users,dc=my,dc=domain,dc=com" write by * read
so this user logs into WGM and can edit any info he has access to but can only read everything else.