Hi gazz,
We don't have the ability right now to determine whether a replay is a club member replay or not. My advice would be to start a "Post Your Replays" thread in your private club that is similar to the one on the public forum. If privacy is your concern you should talk to AvatarLee about the alternative method for sharing replays. He's got a neat little replay tip that might be useful for you in this situation. I'd link you but I can't remember the thread off the top of my head.