[c-nsp] CSS Operation description needed

[Per A]

Sorry for the false-start.
 
I have an emergency request for CSS config and practically no exposure to this platform.
 
General description:  customer has web server that can't handle load.  Server resides in DMZ where ASA provides access and NAT conversion to private address.  To reduce the amount of traffic the original server gets, the customer wants to send requests destined for one directory within the url path to a new server, all other requests to the orignal server. 
 
Here is a link I found providing a configuration example on how to do this:  http://www.cisco.com/en/US/products/hw/contnetw/ps792/products_configuration_example09186a00801c0dbc.shtml
 
So, what I'm looking for is a high level description of the operational path that CSS uses to make this kind of function work.
 
Here is my speculation based on what I've read:  I will change the NAT on the ASA to point traffic for this website to the CSS server.  The CSS server accept the TCP session on behalf of the web server, inspect the HTML GET request to determine the "routing" path and then generate a request to the appropriate HTTP server and pass the response back to the original client, thus proxying the entire conversation.  The CSS server would need an IP address in the DMZ and a port attached in that network, and a default route.
 
Is it that simple?

Thanks in advance for your help (especially on Saturday)!