lucy24 - 6:30 am on Feb 2, 2013 (gmt 0)
Now, wait. Do you want to do this via a php script or in htaccess? (I am going to go way out on a limb and guess that you do not have your own server or even VPS, so we're not talking config file here.)
A simple referer-based redirect is two or three lines in mod_rewrite. In php it will take more than two lines. But then again, you will have more flexibility.
Either way, nobody is going to write it out for you :( But if you are willing to learn how to fish, someone will come along now and then to help disentangle the fishing line.