Robomoderator script

Hello, 
I need to write a script to act as a robomoderator for a 
moderated usenet newsgroup -- i.e. messages posted in the group
are mailed to an address, there is a mail script which processes them.

It's a Unix operating system.  Some starting questions:

-- Is procmail a good program for this?
   If not, what would work better?

-- Does anyone have scripts which are similar to what I need to write,
   described below?

-- Is there a manual for writing procmail scripts?

-- How do you set up a mail alias, i.e. have mail to 
groupname(_at_)your(_dot_)site
sent to my personal address?

-- What do news postings look like when they end up in a moderated
group's mailbox?  What does the header look like?

-- The robomoderator program will do several things:
    -- Look for a specific other newsgroup in the newsgroups line
       in the header, if found, forward the posting to a moderator
       of that newsgroup 
    -- Look for other moderated newsgroups in the newsgroups line,
       take those newsgroups out of the newsgroups line
    -- Compare the e-mail address of the poster against addresses
       on an auto-approval list; if the address is on the auto-
       approval list, post the message to news, with a custom
       message-ID, then e-mail the sender an acknowledgement
       message;
    -- If the e-mail address is not on an auto-approval list, 
       print the message out to a directory file to be looked
       at by a human.

Also, there will be several moderators, processing messages by
e-mail.  I'm thinking of a system where moderators communicate
by e-mail with the mail processing program, i.e. they send a 
message saying "get list" and they get a list of messages to 
be moderated; they send a message saying "get 
how_to_write_robomoderator_software" to get a posting to be
moderated, by that name; they reply to the message and the
script posts it.

What's a good mail processing program to process commands
like this?

Thanks much.