Getting an S2 internship visa for China in Vietnam

Hi, I am currently doing an internship in China with an S2 internship visa, but it has no multiple entries and I will go to Vietnam with my company for 4 days and then come back to China to continue my internship. Therefore, I will have to get a new internship visa when I come back to China. Is it possible to apply for such a visa in Vietnam? And would it be ready in 4 days? If not, do you know what other options I have? Thank you!