Certificate Authentication

Hi There,

I am currently living in Jinan with my wife and baby. I am here on a student X and my wife and baby are on 3 month tourist L which we have just extended.

My university has told me that if I take my marriage certificate and baby's birth certificate to the Chinese embassy in the UK, they can give us a certificate authenticating them and then when we return to the PSB can give them a longer one to expire when mine expires (Sept 2014)

Do you know of this process? We are British citizens.

Thanks!