Since it's a company box, and I assume you had permission to reformat it and load on Win2K, why not ask the IT people if they have drivers for Win2K. At the very least, they should be able to pull up the specs for what they ordered on those systems and tell you exactly what kind of sound card is in it.

There's also the possibility of hitting Dell's website and searching for Win2K drivers for that particular machine. For all the crap Dell spews about custom made PCs, they're really just as canned as all the other vendors. There's only a couple of possibilities for what sound cards they will put in particular system models (usually 3 or less), so even using trial and error methods it shouldn't take too long. Just make sure the drivers are for the Chinese version of XP if there's an option. There are sometimes subtle differences between the version of Windows that uses alphabet based languages compared to those that are more idiographic beyond just the language aspect.