Visa to enter Hong Kong and Macau after a visit to china

Hi, my name is Miriam - I am Egyptian , visiting in October 2012. I have a single entry visa and would like to visit Hong Kong and Macau .So can I do this or my visit should be a multiple entry to be able to do this? And what should be the best scenario to be able to visit at least one of the 2 destinations after my 3 days visit to china mainland? Thanks in advance