How can this be done? I'm sure nGlide or some other Glide Wrapper will work, all other games that can use it and that I've tried worked almost flawlessly but I can't change it, there's no option for it.

I found the glide3dfx.exe on the net as a retail version and a fix, both doesn't work really work. Either I have to play in emulated 3DFX mode and that requires safe mode and with that I've no sound or I try the D3D.exe and the game freezes no matter what settings.

You will have to use win98 compatibility mode for 3Dfx to work with sound.
I'm now playing mine with D3D though, also have to use win98 compatibility and use HAL only, pre-load chached files turned off too.
Still this game is very unstable and wants to crash at every opportunity, one of the reasons that after 10 years I still haven't played to the end, it crashes at least once every hour or so and then I have to use safemode to reset the video settings again. =(

I've tried all compatibility modes, nothing works. I noticed now that after a while a text arrives saying "no audio files could be found on the cd!!" or something like that, with all 3 different sound settings (non-eax, eax, software).