In the above example, the /yyy would be preserved in the request so that it would still be there when it got load balanced to the rserver that requires it. Only the hostname would be changed from xxx to yyy. A redirect rserver is documented here.
On the other hand, to meet your current requirement, if someone comes to the ACE requesting https://www.yyy.com/ then you could redirect them as follows:
Can you elaborate on the configuration a little more please, i am attempting to do the same thing but my rewrite config matches the traffic again when it returns and so loops, you can see the hits on the redirect server are 2000ish for one web request. My class map is matching on ip and port. I can’t seem to implement a policy map that doesn’t match and ip/port.