Good afternoon,
I'm not sure to understand why you need to rewrite the host header or send the request back to the other VIP.
Since you are doing SSL termination, the backend connection (the one between the CSS and the server) will be using HTTP, so, the domain name would not have any impact.
What you should do is create a new SSL termination VIP and map it to the same HTTP content rule or server.
Don't hesitate to contact me again if you need further explanation on this.
Regards
Daniel