I see similar questions, but not my exact challenge.

What I have done so far I cloned a prod server over to a vmware to use it as a test server for new functionality I'm going to write. I'm not a sysadmin by trade, but I'm new to this company and I have to do some thing that are outside of my comfort zone (thats a good thing :) )

The prod server has 2 sites on it s1.com and s2.com. In /html/s1/, /html/s2/ there's an .htaccess file under each s*/. Looking like this:

RewriteEngine ON
RewriteBase /
RewriteCond %{QUERY_STRING} id=([0-9]+)        
RewriteRule ^.*  %1.htm
RewriteCond %{QUERY_STRING} page=modules/checkout
RewriteRule ^.*  order.php
RewriteCond %{QUERY_STRING} page=pages/sidekart
RewriteRule ^.*  pages/sidekart.htm

The issue is that s1 has a lot of pages that really belongs under a third domain s3, the rule in line 4 and 5 redirects them to /html/s1/. An example of such URL is: s3.com/?page=modules/product&id=521614

I'm trying then to get those URLs (without modifying the URL) to redirect to s3's /html/s3/ server structure, which I set up making a new virtualhost s3 in test servers httpd.conf with a test3.com as servername and changing the other sites to tests1.com and tests2.com, and adding .htaccess also to this s3 root directory, and making a html/s3/ directory structure I populated with an index.html, etc.

But, when I take the same URL (s3.com/?page=modules/product&id=521614) changing it to tests3.com/?page=modules/product&id=521614, I get s1's index page showing up in my browser. I've poked around about a day now and i cant figure out why this happens.