Yes, I do.
Seems like I explained myself not clear enough, sorry.
The problem is as follows:
I use Chrome's Advanced REST Client application to test a server's functionality.
When I send request to the "original" url from the opening post, I get a desired response.
But when I send the same request from the HTML5 app from the HCP using destination, the server's response is differs from the previous case.
The differences between two requests are the "Origin" and "Host" headers (basically, the request url).
The question is how do I fix it on the HCP's side?