file associations

I have many files in strange formats that can be opened by applications that are not installed by default on any Linux distribution. How do I teach KDE to recognize these files based on their endings (like .ab1) and to open them - when clicked - with the correct application? Go to Control Center -> KDE Components -> File Associations -> Add -> Leave Group "all" and type in some short, descriptive name (e.g. ABI trace file) -> Under "Filename patterns" put the file extension (or any other pattern that enables KDE to recognize the file; e.g.