radiusd log filename

Hello freeradius-users, I have some radius instances started by name (radiusd -n xyz -d /opt/freeradius/xyz/etc/raddb), which by default generate log files as /var/log/radius/xyz.log. I would like to change daemon log filename to have a YYYYMMDD suffix, in order to have an automatic daily log rotation, but this does not seems to be supported, as log_file does not seems to expand variables as this can be done for request logs or acct detail. log_file = ${logdir}/${name}.log works fine, but log_file = ${logdir}/${name}.%Y%m%d is not expanded and generate /var/log/radius/c4france.%Y%m%d instead of /var/log/radius/c4france.20100312... Is the any way to achieve this setup ? Best regards Fred