Emoji are text. Which text editor/browser/settings should I be using to ensure I copy your reply accurately?

With the exception of (sigh) newlines, I surely hope your text editor accurately records the characters you paste into it. This job isn't different just because the characters are strange, multi colored ligatures.

Edit: As long as you work in UTF-8 that is, but you have to go out of your way to use any other encoding as an interchange format these days, even if alternative internal encodings aren't uncommon-