I've given this some thought but due to both my lack of knowledge in Japanese (still studying atm, although in Japan for a year so that should improve) and just not being able to come up with anything that sounds right with what I do know, I'm not even sure if this is like a thing to say in Japanese. Either that or I'm just getting tunnel vision on this and missing an extremely simple way of translating this.
But so yeah, is there a way to say like "Bob says hi by the way," like when you were talking about one person with Bob earlier and then Bob tells you to extend his greetings to that person the next time you meet?