Going to resurrect this post since it was the only one I could find when searching Google and I actually did get the card to work in Win98 after a few days of trial and error.
The link synrgy87 provided is in fact correct: https://archive.org/details/sb-install_202005 but what you need to do is run CTZAPXX.exe from the \Audio\Drivers folder. The only option available will be WDM. I haven't been able to sort out VXD after trying nearly every Audigy 2 Value install I could find on the internet, this is the only one that will actually recognize the drivers with an SB0400 and I don't see VXD in the install unless I am missing something.
It should take around 5-10 minutes for the install to complete, if the system hangs after asking for the Windows 98 disk, just reboot the system and the drivers will still show up and work (You can also uninstall the device and let windows re-install the driver on startup if you are worried about a bad install.) I also noticed that running the install from the desktop instead of a mounted image seemed to be bit more stable but nothing to substantiate that claim
Trying to manually install the .INF will also not work, once Windows is done installing on reboot it will just show Creative Audigy Audio Processor (WDM)" with a yellow exclamation mark.
After install I tested the card with a few games. Half Life GOTY would hang when enabling EAX but Undying and Creative Goldmine EAX Demo both worked without any issues. I will test some more titles out when I have some spare time but it does appear to be stable and working. Will also update thread if I can figure out how to get VXD drivers to work.

Specs used for testing:
P3 1G 100 Slotket
512 100
p2-99 Mobo
AMD 9250 128/128
Cheers!