Please read carefully what im going to say, it will help you a lot.
-----YOU WILL NOT FIND ANYONE WHO CAN DO THIS.-----
why?
-----BECAUSE ITS TECHNICALLY IMPOSIBLE.----
why you have to trust me?
----BECAUSE IM A SECURITY ENGINEER WITH HMAC EXPERIENCE AND HACKING.
So, if you want i can help you explaining this more deeper and technically.
Also i can help you to get the HMAC cookie always.
Please, understand what im saying.
Regards,
Fabrizio