Help : Semi Private Plone site (french univ)

Hello.
I'm developping a plone site for a french university committee , which
receive documents from research teams and must evaluate and approve them. I
have some problems concerning the privacy and the access to some documents.
There is a public part in the site (document visible to everyone, and
searchable by the searchbox)

There is also a private part: the committee must see (but not edit, only the
comitee's secretary will have the edit document permission) all the research
teams documents, and each team must create only his documents.

(it's like an enterprise. The client A creates his order, the sale's
departement reads it, and create a bill, and the client A can see it. Its
the same for client B (the sales departement can see every orders and every
bills, but client A sees only his documents)

How can i succeed to this?
- By using archetypes to implement permissions in the documents types?
- By using a special workflow ?

I've tried to use the local role method :

I've created a new role which has the read and edit access.
Then i go to the members folder in the ZMI, acquire permission is unchecked,
content access and edition is unchecked for everyone except for a this new
role, and i give this new role to each user, but only in their folders, as a
local role.
But it's not an esay way for the committee secretary, i didn't want her to
go to the ZMI each time there is a new team sending a case to the committee
(40 cases a year). I thought using GRUF could help, but i did not see a way
to use an automatic group/role attribution for new members

Any help would be appreciated...thanks in advance.




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