[Dovecot] global sieve script

hi all,

i'm moving from a maildrop+courier setup to lda(sieve)+dovecot setup.

with maildrop i had a global filter for all the users, so i could filter and archive into the spam folder spam tagged emails for users without custom filters, including them if they exist:

LOGNAME=tolower($LOGNAME)

test -e $LOGNAME if ( $RETURNCODE != 0 ) { maildirmake $LOGNAME maildirmake $LOGNAME/._spam }

test -f $LOGNAME/mailfilter if ( $RETURNCODE == 0 ) { include "$LOGNAME/mailfilter" }

if ( /^X-Spam-Status: YES */) { to "$LOGNAME/._spam" } else { to "$LOGNAME/" }

how could i get this behaviour with dovecot lda and sieve ?

thanks !