So we've downloaded the multiplayer-enabling mod, that works fine (eventually). Multiplayer option works.
We've tried Hamachi and Gameranger (GR doesn't work because it doesn't have a hellfire option)

The direct-connect option is the only one that works, and neither of us can see an active game.

I see people saying that you need to run it on IPX which makes sense, but that option won't work.

I've been dying to play this multiplayer for years someone help !

you need the ipx wrapper from this website to get ipx working: http://www.solemnwarning.net/ipxwrapper/
direct connection involves using a serial cable.

Friend tried this as I posted, works fine now thanks!