I wrote MODERN and not MODEM !!
For a DOS boot environment that supports huge numbers of NICS, have a look at:
http://www.netbootdisk.com/
You can then use the HP utility for making USB sticks DOS bootable and add the netbootdisk stuff onto the flash device. Just be aware that depending on the way the bios works on your various systems, some may mount the USB stick as drive A (recognising it as a floppy disk) and some systems will mount it as drive C (recognising it as a hard disk). So any batch files you use need to figure out what drive letter the USB stick mounts as.
However, it is soooooo much easier with WinPE that you would be much better off just working with that instead of DOS. Since most hard disks and optical drives are now SATA, your DOS boot is pretty much worthless now, as DOS cannot work with SATA devices unless you switch them to IDE emulation in the BIOS first.