ACLs using members and groups

Hi, I have a question regarding ACLs and their use in an interesting circumstance.

I have a group, lets call it g, and it contains users a and b. I also have users a, b, c and d. Now, I want user d to be able to have access to write to the members of group g, and unable to access non members of group g. Now lets say i add user e, and e becomes a member of g, i want d to be able to write to these 3 members (a,b,e) without needing to rewrite or insert ACLs etc.

I have been looking alot at the ACL page on the openldap site, and as much as i think the group and regex rules are fantastic, I cant think of how to implement them for this situation. Any help would be greatly appreciated

Thanks for your time and help, yet again.

William