You can download the w2k boot disk set easily, or create it yourself if you have a w2k installation CD, but those floppies are designed to get you to the Recovery Console or to help you install Windows -- It's not true "MS-DOS mode" (for good reasons).
If you want to get into DOS mode, use a Windows 98 or ME boot floppy (you can use even older boot disks too, but they won't include generic CD-ROM drivers or FAT32 support).
Note that if your hard drive is partitioned using NTFS, you'll first have to delete your partitions & recreate them as FAT32 in order to access your HD from the boot floppy.
You can download Windows boot disks here...
www.pchelplive.com
From there log in with with my account below (or create your own):
Name: bootdisks
Password: password
then go to the downloads page and click 'Windows Boot Disks' in the bottom right. From there you can get a copy of the boot disks that came with everything from DOS 5 to WinXP.