My apologies, I guess I misunderstood your question.
I've never configured stickyness based on a cookie-value that is not sourced from the ACE itself, so I really couldn't tell you if it would work. But according to the doc, the ACE can be configured to dynamically learn portion of the http-content (e.g. cookie) and provide stickyness based on this.
In my experience though, when parsing the http-header for specific content, there is one thing in particular you need to ensure. By default, the ACE only parses a certain length of the http-header (2048 bytes), so if the http-header exceeds this length, you might fail to locate the cookie value and your stickyness is lost. I've had this happen to me and the solution is to create an http-parameter-map and configure a parse-length of a higher value (e.g. 8k).
Also, I think persistence-rebalance is required, unless you only want to inspect the first requst and simply "switch" all subsequent requests to the same rserver.
Introduction This article will help you understand the steps on how to
download the UCS licenses from the Cisco Systems website and then
installing it on the UCS. The redacted (blue lines) just covers up
certain numbers for privacy please do not take them...
Introduction This article will help you understand and educate the
customer on how to clear their "expired licenses"
(license-graceperiod-expired) from their UCS-M. If a customer just
purchased a license and needs a step by step guide on how to download
Introduction Prepositioning is a powerful tools on the WAAS platform but
it is not always easy to figure out why your jobs are failing when
trying to retrieve the files.Here is a method that should help you to
figure out the reason why they are not succes...