Edit:
So I use a temporay file called mailtemp to store the intermediate processes
This is my qmail part of /etc/cron.hourly/awstats
find /var/log/qmail/ -mmin -60 -name "\@*" | xargs cat | /usr/local/bin/tai64nlocal > /var/log/qmail/mailtmp
cat /var/log/qmail/current |/usr/local/bin/tai64nlocal >> /var/log/qmail/mailtmp
perl awstats.pl -config=qmail -update >/tmp/null
and this is the part of my awstats.qmail.conf
LogFile="perl /home/e-smith/files/ibays/awstats/cgi-bin/maillogconvert.pl standard < /var/log/qmail/mailtmp |"
Feel free to comment and improve
Mael