Automatically sort groups into topics

[John Ankarström]

Hello,

Does anybody know of a way to automatically sort groups into
different topics? More specifically, through Sieve filtering, any
mailing list I subscribe to has a folder created for it, inside
the Lists IMAP folder.

In Gnus, this results in mailing lists groups being prefixed with
"Lists." - and I'd like to put all groups beginning with "Lists."
into the topic `lists'.

Any ideas?

- John

PS. Bonus question: is there any simple way to write a new
message to a mailing list from its summary buffer? When replying,
`S L` is very helpful, but that includes the original message. I
would, at least, like a `S l` that creates a new message to the
mailing list without the original message, but ideally, a whole
nother command that keeps only the To: field but clears the
Subject: and message text.

(Thanks!)