Please offer some advice.

Guys, can someone share a patch and instructions on how to play Heroes 4 online?

Install Equi, and you'll be happy. If you have the original version, you'll need either Vortex/Storm (you know where to get it), or the patch is in the same place as Equi – after that, Equi should work with the original version. Also, if you really want to play the original version, you can get a patch for online play from Buka.
And then, either use Hamachi, or enter direct IP addresses if you have them. Hamachi is an emulator of a local network within a global network (the internet), so if you're going to play on a local network, you don't need Hamachi.