Modrewrite Without Explicit Redirecting

I have this as my .htaccess

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule !(index.php) [url][L]
</IfModule>

It works in every way as desired.

Any url, [url]whatever will show up [url]

From index.php then I can create php generated websites that take pics, whatever from database.

However, I got an idea. What about if several domain names use the same index.php and the same database. So, it's like mirrors.

If I put the same .htaccess in other domain name, I got something unexpected though.

The url location actually change to [url]
Also the content of

PHP Code:

echo 'Server:' . $_SERVER['SERVER_NAME'] . "
";
echo 'Host:' . $_SERVER['HTTP_HOST'] . "
";
echo 'Request:' . $_SERVER['REQUEST_URI']; 

also change to domain.com, and /index.php?languageIndicator=lang_ar

I want an implicit redirect. Not an explicit redirect. To the outside world, people must think that they're indeed accessing http://otherdomainame.com/somepages and has no way to know that the page they're looking is http://domain.com/index.php?languageIndicator=lang_ar

How can I do that?

Of course, I can always copy index.php to all my domain names. But that's slow.