For example , you push Ctrl+V and insert the buffer content into the window. How can I create my own hotkeys like that? Sorry for noobish question.
First, welcome to Stack Overflow!
Second, this is a program by program thing. The only reason that Ctrl+C or Ctrl+V works across different programs is because there is operating system support for the clipboard and many programs follow the convention of using Ctrl+C or Ctrl+V. In your own programs, you can bind the keys however you like! For more details, we'll need more information about your program.
If you want to make actual hotkeys for Windows itself, I'm not sure how (nor if you are able) to make your own hotkeys. You might want to look into AutoIt, which is a free program that can do all sorts of things you might want to use a hotkey for, such as automatically clicking through menus, etc.