The problem is, most AC97 sound cards are PCI based and DOS has been abandoned by PCI based audio device manufacturers. Almost all of those devices don't provide compatibility with older sound card, or the manufacturers don't give any effort on providing a software solution for compatibility with older sound card.

Even if the AC97 sound card is ISA based, if it doesn't provide compatibility with older sound card, the DOS game only know a limited number of sound cards. And the chances are slim that it's one in the list.

Also in my gaming experience since 1988, no DOS games support soundcards by utilizing the AC97 standard. All of them utilize sound cards directly to their vendor-specific chipset I/O.

DosBox would be the ideal solution, but if you don't want to use it, you can use VDMSound which is a SoundBlaster (up to SB16) and AdLib / Yamaha OPL2+3 emulator software (for Windows 9x/ME only). A payware unfortunately. But it works for most games - assuming that they support SoundBlaster and they're not hindered by the Windows itself.