Keyboard shortcut for small caps

Is there any way to create a keyboard shortcut for small caps? The shortcut settings let me add one, but when I try to use it nothing happens. I’ve searched through previous posts and can’t find anything on this topic.

Something to note is that this command works on existing text. It is not like bold where you can use the shortcut and then type in bold. You have to select text that you’ve typed in and then use the command. It will convert font sizes and change the capitalisation of the letters to achieve the effect.

I’d also note that if you have a font with small caps, it might be better to use that instead of the above, as a hand-crafted small caps font will look better than using all capitals and changing the font size on some of the letters.