you can add new cheats to vcmi in addition to vcmiglaurung, vcmieagles etc. etc.?
If you want then you could tell me how to do it?

Adding them via programming (extending VCMI code) is the only way for now

Imagine, do you know how I can do to add them?

Yes - check CGameHandler::handleCheatCode in CGameHandler.cpp file - it belongs to VCMI server

You can as well just suggest it on bug tracker as feature request. If cheat code would make sense then someone of contributors can add it.

I added the code in game handler as you suggested, but to insert what the code should do as it does?
I would like you to join some dragon faeries