I was suggesting you have a look at the GFN plugin code not the thread, it's the zip that's attached to the first post.
FWIW: I use a gadget that comes with the Transtools add-in for Word to insert single special chars, I think its packaged with the free version of Transtools, I have it set to pop on Ctrl+Win+S, viz:
And Clipboard Fusion is good for boilerplate snippets, I have it set to pop a list of named snippets on Alt+Win+P.
For this sort of thing I prefer tools that work everywhere, rather than application specific tools.
BR