renice a process after boot

["dan" <dan@mbs-us.com>]

I have DNS (BIND 9.2.1 from the package) on OBSD 3.2 running on
an old Sun IPX, I'd like to renice the named to -10 or so upon
reboot (just to make sure that if there are any
cycles lying around they will be used for that)

I tried the following in rc.local:

sleep 5
/usr/bin/renice -10 `cat /var/named/named.pid`

but upon reboot it says there is no pid file.
Is there any incantation of cron that will go off only after 
all the processes have started on reboot, giving named
time to create the pid file?  What other options do I have?

thanks for any tips,

dan smith