here.
or on linuxmint forums.
that's the literal answer to your question, but i guess you want more than that.
you want to copy something into the clipboard, and, maybe by pressing a hotkey, automatically open a text editor and paste the content?
some scripting and a utility called
xdotool can do that.
(maybe you also want xclipboard, but i have never used that)
i suggest you just install xdotool, then open a terminal and type
and see where that takes you.
it's a different question how to create executable (shell) scripts, and another one which desktop environment you use and how it handles hotkeys (aka keyboard shortcuts).