EasyBCD won't let PC-DOS dual boot with Win 7

I have successfully created a dual boot between Windows 7 and DOS 6.22. using EasyBCD 2.1.0. However when i tried that with PC-DOS 2000 it didn't work. (Followed the same exact procedure as that of DOS) to no avail.My question is, why and is there any easy way, like editting something in bootloaders or config files or easybcd itself, or like that. to achieve this?
Would it have anything to do with MSDOS.SYS and IO.SYS having different names in PC-DOS?
Any help or at least some insight is really appreciated.
Thanks in advance.
Naomi Furukawa