Google-groups – Reply only to message author on Google Groups

Prologue

I created dozen of groups on Google Groups that functions as below (P.M. = personal messages; G.G. = messages sent to Google Groups group):

 ----      --------------------
|Boss|    |External Environment|
 ----      --------------------
   ^                 ^
   | P.M.            | P.M.
   V                 V
 -------------------------------
|         Group Manager         |
 -------------------------------
   ^                      |
   | P.M.                 | G.G.
   |                      V
 -------------------------------
|           Employees           |
 -------------------------------

I.e. those groups are only announcements that Group Manager must do to employees (Announcement List). Employees must answer the messages sent to Group Manager only to Group Manager, i.e., none would see the answer, but the Group Manager (and the employer that sent it, of course).

What we want

We are searching for a way to a employer answer G.G. messages directly and this answer to be sent to Group Manager only, not to all Google Groups members.

Issues

1. Default Google Groups configs: Don't match specs, since if a employer answer the Google Groups it will be received for all members.

2. Changing all configs to disable user posting: Don't match specs, because when a employer send a messages to the group, it fails and he/she will receive a delivery failure status notification.

3. Changing to default but on Posting Configs, selecting Answer to Author, all, and on Details, E-mail Options, Post Answers to Managers: Don't match specs, because all users continue receiving answers from a employer to the group…

Help

How to do it? Only with orders to answer putting Manager e-mail manually on TO field?