[Dovecot] + sub addressing setup

I have Dovecot/Postfix/MySQL/PostfixAdmin,

I'd like to setup + sub addressing (for +spam and possibly user-defined +folders)

I have setup a user+spam folder path in PostfixAdmin as so;

vvv+spam@tld path:tld/vvv@tld/.spam/

that requires me to put a 'duplicate' user with the + and +path for each user, the folks on PostfixAdmin suggested that Dovecot might have a better way of handling this, how do I accomplish this in Dovecot ?

thanks for any suggestions or tips

-- Voytek