[support] Organic Groups - Moderating Group Owner/Group Subscriber Roles

[Moses Elias]

I am using Organic Groups with Drupal 6. Any group can be created by
authenticated users.

How do you promote a group creator to "group owner" role, and how do you
promote somebody who joins a group to "group subscriber" role (where they
can post to groups).

The fundamental difference between a "group owner" and a "group subscriber"
role is that a group owners can edit/delete posts within his group (and
possibly change workflow) - and I want this distinction maintained.

Which module would most effectively achieve this?

(I have tried Organic Groups User Roles module, but that doesn't seem to do
the trick in a simple and effective manner.)

Thanks for your help.