I dug around a bit, but I couldn't find any DOS driver for that card, either. The only thing I can suggest is to try running MPXPlay with the -sct command switch, and hope that it is able to recognise the card.
If that fails you could try asking MPXPlay's author to add CS4299 support to MPXPlay. The chances aren't good, though, unless he owns a motherboard (or soundcard) that has this particular chip. Doesn't hurt to ask, though.
Im looking for a DOS sound driver and have spent days googling around without any joy and pulling my hair out. Thought maybe someone here might have one sitting on a dusty floppy somewhere. Chip on the board is a CS4299-JQ. (Cirrus Logic Crystal) Its for an HP e-vectra mini pc. Its a very cool small system and perfect for a portable jukebox or car jukebox or both. Ive got DOS 7.10 installed fine and everything works except sound so obviously mpxplay plays but without sound, arghhhh. I tried all the drivers (which wernt many) in the DOS 7.10 install process but none of them work. Surely it is soundblaster pro compatiable or something? Ive come to a dead end, and have serious insomnia as i dont give up easily, lol.