How to play Colin Mc Rae 2 with a friend?

Hello

I'm newbie with Hamachi and with networking in general.

My friend and me installed Hamachi, but we don't know how to play online?

I created a network and my friend connected to it. We could talk in the Hamachi chat without problem.

Then I started a Colin Mc Rae 2 game as a host. My friend tried in CMR2 to find my session but he couldn't do it. He put the IP which is shown in Hamachi but he didn't find my game session.

What are we doing wrong? What do we need to do (in easy and complete words) to play? Firewalls are disabled.

Thanks