Do well there or in there?

Hi. Please help. As to the phrase "in there," I think we use it when we want to say something about something being inside a three-dimentional place like a room. Let us pretend someone wants to tell his friend who is entering a contest very soon to do his best, could he say this, without using the phrase "in the contest"? Let us also pretend the person's first name is John.

Hi, John. I heard you are entering the contest. I hope you do well there (in there?).