I'm new to CC universe, but might I suggest playing through GameRanger? www.gameranger.com
It is a lot easier in my opinion than Gamespy and Hamachi, just host a game, people join, and when you start the game, it already moves you to the multiplayer menu (at least Age of Empires, Red Alert 2, Age of Mythology and Heroes 3 that I played worked everytime), all CC games are supported (don't know about mods though).
PS. Very eager to play, i have CC 1,2,3,4,5 but no mods (new to the universe, as said - ready for suggestions)
In August of 2004, Zappi, Homba, Bambam887, RedScorpion and MOOXE all pitched
in to create this Close Combat site. I would to thank all the people who have visited
and found this site to thier liking. I hope you had time to check out some
of the great Close Combat mods and our forums. I'd also like to thank
all the members of our volunteer staff that have helped over
the years, and all our users that contributed to this site!