Try Smart Boot Manager: http://btmgr.sourceforge.net/
It should do the trick.
From: Jeff Engstrom [mailto:Jeff dot Engstrom at fortix dot net]
Sent: Thursday, December 18, 2003 2:51 PM
To: 'm0n0wall at lists dot m0n0 dot ch'
Subject: [m0n0wall] CD-ROM Boot option no available
Any ideas on how I can boot to the CD without BIOS support?
Perhaps a boot floppy that loads the cd rom drivers... then boots to CD?
Thanks for any help in advance!