Arriving Guilin fr New York with 18 hr layover in Beijing

I will be going to GL from New York via Air China. I will have an 18 hr layover in Beijing,so i booked a hotel at downtown area. My question is, will my baggage be check through to GL or not? Since i am leaving the airport for my hotel. I presume that i have to go through immigration ,when i come back the next day do i have to go through immigration or am i considered a domestic passenger.? Thanks.