Organic Group and simple ACL

Hi,

I need your support, i've installed the OG modules and Content Access/ACL.

I've need to "extend" the OG Audience (Private/Public) adding some users (acl) to a post in a group, also if the users if not in the OG or is in another OG. Only this, without the complicated questions if TAC/OG_USER_ROLES/CA/ACL things..

Can you give some info to resolve this ?

I've tried all, but it's all complicated (mixing the Vocabulary in the permission and some strange things like this..), i want only normal OG permission + adding some external users.

Thank you very much