Have you done plot resetting before? This is basically the same idea. When you turn on the game for the first time on a new day (by new day I mean past 6 AM since that's when a new day in AC begins), do not load up either your mayor character or any other alternative characters. Instead, create a new character. Go through the conversation with Rover until you make it into town. Then, go to the campsite. If there is no camper, or there is a camper you don't want, turn off the game, and repeat making a new character until you find someone you want. Once you do, progress until you get the TPC and the game will save automatically. Afterwards, save and quit, delete your new character if you wish, and when you load up on your mayor/any existing characters, the same camper will be in the site.
It basically takes advantage of the fact that every single time you create a new character, the game's state is created but not saved, because you don't save as a new character until you plot your house and get your TPC. A dice roll occurs every time the game's state is created, dictating whether or not you get a camper, which camper it is, etc. Again, this can only be done if you haven't loaded up an existing character for the day. When you load up an existing character, the game simultaneously loads and saves the game's state (when Isabelle is doing her little spiel). Because it saves, any camper in the site is created and saved at the same time.
That being said, I really don't recommend it unless you are desperate. You won't always see a camper. On average, I've found that you get maybe 1 in every 10 resets. Some days you see more, some days you see less. Some days (like holidays), you won't find them at all. I've heard that Sundays are a good day for campers, but I don't think there's been proof.
And no, you can't have visitors pick up the camper.
