Working Visa Processed in Korea? (Beijing)

I have a friend who is visiting on a L tourist visa and was offered a job with a company who is going to give her a Z working visa. The company told her they will prepare the paper work and she can process the Z working visa in Korea instead of having to go all the way back to her home country. Although it is ideal to return to your home country, is it possible for her to do it in Korea? If so, how does it work?