It depends on which emulator you're using, and possibly the version. I use Minus4 for Windows which does not seem to have a C= key (Mike, can you verify?), but I also use an old program called Plus4 that uses the left Alt key as the C= key.
My recommendation (if you wish to try to find it on your own) is to enter the built-in software, and try various keys with the C (as in cat) to see if you can get the > prompt at the bottom of the screen.