[Dovecot] Making both folder and .folder available to dovecot-lda but not imap

[Stand H]

Hi,

I'm looking for a way to deliver mail to both 'folder' and '.folder'. I put 
LAYOUT=fs to mail_location, sieve recognize both 'folder' and '.folder', but I 
don't want dovecot-imap to show 'folder' to imap client. The purpose is to send 
some emails to 'folder' and don't let user to see the folder and email in it.

I'm using dovecot-1.2.13 and dovecot-1.2-sieve-0.1.17. Can someone help me with 
the configuration. Thank you.

Regards,
Stand