How do you replace output characters once they are on the screen in Visual C (command-line)?

If I want to make a countdown timer, for instance, and have it display 5, 4, 3, 2, 1 but the 5 replaces the 4 and so on, without modifying the rest of the screen output, how would I go about that? Something like a goto function, but one that goes to a spot on the screen instead of a spot in the code. If anyone has any idea what I'm talking about, please give me a hand... I've been searching for about an hour.