Tranfer to international flight from an international flight which aren't Connected to eachother in Guangzhou airport

My flights are istanbul-shanghai on 28th feb. and GZ-İstanbul on 12th march. i have only one enterance VISA to china .but also i want to go to Hong Kong before leaving china from GZ. My questions is if i leave china and get back to baiyun airport by plane from hong kong to GZ will they let me transfer to my last flight to İstanbul? if The answer is yes, will i be able to get my luggages back from Hong Kong flight to carry to İstanbul flight?