modify group name

[Sébastien Kirche]

Hi,

I sometimes access to some of my OSX Mail.app archives by creating a new
group with gnus-group-make-doc-group (Mail.app  stores the messages in a
mbox format)

There  is  no problem  to  read the  messages,  however  I have  several
mailboxes  within   Mail.app  that  stores  each   mailbox  in  separate
directories  in a  'mbox' file.  Thus  the resulting  groups are  called
'mbox'.

When i try a G r gnus-group-rename-group  on them I get a "This back end
does not support renaming groups"...

Is there a convenient way to  rename them by an other mean that tweaking
the .newsrc.eld file ?

Thanks.
-- 
Sébastien Kirche