Changing partition from the command line?

[Sysadmin.]

I'm working on a system which is running a 6386 AT+T machine with AT+T Unix
System V/386 on it.  Here's what I'd like to do.  The hard drive is partitioned
with a unix partition and a dos partition.  At a specified time, I would like
the computer to AUTOMATICALLY change the partition to the other one, and    
reboot the system so that the other operating system comes up (perhaps doing
it from cron on the unix side).  Is there anyway to change the partition
with out fdisk being interactive (in other words, strictly from the command
line so that it doesn't require that someone be there)?  I would like the
machine to run unix at night and run dos during the day.  But, I can't be
there to do it manually.  Thanx in advance.

P.S.  Does anyone know of a TSR that will do the same for dos?

-- 
Jesse W. Asher - Dynasys - (901)382-1705       Internet: jessea at dynasys.UU.NET 
6196-1 Macon Rd., Suite 200, Memphis, TN 38134     UUCP: uunet!dynasys!jessea