Salam, As the Medical Examination for CE-2012 has been announced, I need to inquire whether it is possible to postpone one's medical exam, if someone is having sound reason(s)?

I am currently in Xiamen University, China, pursuing my Masters Degree, having first semester, that is going to be completed by the end of the next month i.e. Dec or in early Jan, and now I have this Medical Exam to appear in. Seniors and others please guide me in this regard ASAP..!!! I would be indebted to you for your assistance.