Ok I found the program, but when I am trying to open it, a small black console windows opens and disappears after 0,5 sec :/
I managed to find out that I need to create a shortcut of the ResourceExtractor and changing the target to "C:\Program Files (x86)\Steam\SteamApps\common\Hammerwatch\editor\ResourceExtractor.exe" map piratecove.hwm", but still the same.. getting crazy here -_-