I've been wanting to play a network game of C&C for about a year now, however I didn't want to dirty my computer with Win98, so I wanted to use an alternative. Dosbox seemed like the answer when 6.2 had IPX support. When I run C&C without initialising an IPX server/client, but having it enabled in the config, C&C detects the emulated card, although it cannot detect any other computers (of course). When I do enable a server, and when another client connects to it and selects the IPX network game option in C&C, we get this lovely DOS4GW crash:
http://members.iinet.net.au/~blillie/cncipxcrash.png

Hope it helps if you weren't already aware of it. Sorry about the cursor, I took it through a VNC window.