If I understand you right.. you get a win2k firewall and want socks4-clients in Debian? or the other
Either way you will need to know what port is open to communicate outside the wall... (not filtered)
Netscape know how to use a a proxy (your firewall) to communicate.. else.. you get to do some trick
Anyway... First thing first..
1, Test your client to server connection... (client ping server) if that not working.. :) somewrong
before the firewall..
2, Test the open port on server... (don't know win2k) by seting the port in Netscape proxy port to
your server config.
Hope that help