If your NLE supports Red as a plugin, you can simply put it over the portions of your timeline where the clock is needed and adjust accordingly. I assume you know that Red can generate timecode and clock time internally? It almost sounds as if you want to videotape a clock and then use Red as a compositing tool to place it over your video.
Another way would be to set up whatever clock “times” you need in Red running on its own and render them out as Quicktime movies that would be imported into your NLE later. HTH.