Dual boot win2k and nt4

Okay, I’ve seen numerous questions (and answers) for dual booting scenarios where NT or 98/95 was already on a system. I have a situation with a machine that had NT 4.0 (sp4) installed, was upgraded to Win 2000 workstation and now has to also have NT 4.0 (again with SP4) reinstalled (dual boot capable) to run some specific software. The machine does have to hard drives in it so I can install the NT on its own hard drive but getting that done and haveing the win 2000 dual boot manager recognize that NT is there is my problem. Help! Has anyone had to go backwards like this? Any suggestions or recommendations please. Thanks.