radiusd log filename

[Fred MAISON]

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