Amavisd configuration to have spam_quarantine into junk folder

[voltron81]

Hello,
I'm realizing a mail server and I've used the howto forge tutorial. Just perfect.
I'm using ISPconfig3, Postfix and Roundcube.
How can I set up the system to move all the quarantine files (spam_quarantine) to the junk mail?
I've read a bit about amavisd. With $spam_quarantine_to= i can say to the system to send all the spam_quarantine to a folder of the server or to an email address.
The problem is that I can send the spam_quarantine just to a folder... so I'll have a folder where I can find the spam_quarantine of all the emails.
What I want to realize is something like that:
the system will copy the spam_quarantine to this folder:
/var/vmail/%domain/%user/%.Junk/new
So that every email will have in the junk folder his the spam_quarantine.

Any idea to how to realize it?
Thanks
Michele