No, there is not a method for creating group policies in LDAP. This is a function that requires Active Directory.
I assume that previously you used the local security policy area for restricting access to specific areas in Windows. Perhaps you need to look into other options... K-12 environments typically use other apps like "Clean Slate" - Fortres for doing this kind of stuff, protecting student labs, etc.
Creative Business Solutions
IBM, Microsoft, Novell/Suse and Sophos Consulting