You can't just use a "DOS emulator" -- as the Windows XP Command Prompt is the best DOS emulator out there. What you actually have to do to run it in emulation is get a program that emulates the entire PC -- processor, RAM, sound and video cards, etc. Which, obviously, is a lot of work (as the CPU alone must do the work of an entire computer) and thus relatively slow.

You may be able to use an open-source PC emulator like Bochs. For full PC emulation, though, you need commercial software, like Connectix VirtualPC.