Is there a "@testing" in comments plugin/code?

For my website, in the comment area I’d like for commenters to be able to have “@testing” when they need to reply to someone, except they’ll be a “reply” button, and once they click that the comment area will have “@users name” then their respond. And then the user’s name would have a link to the permalink of the comment that the person was replying to.

Sorry, it’s quite confusing, it’s bcause I don’t have threaded comments. Is there a code/plugin I could use for this? I didn’t really know how to search this in the plugins area, like what’d I call it.