htaccess subdomain rewrite to variable without being visible in the url - php

Question

I need to convert "subdomains" to variables using htaccess.
But I don't want the original url to be displayd after the rewrite.
Here's what I have so far:
rewritecond %{http_host} ^([A-Za-z0-9-]+)\.mysite.\com$ [nc]
rewriterule ^(.*)$ http://www.mysite.com/$1?aff=%1 [nc]
But it doesn't seem to work.
What I need is the following:
User links to:
aff1.mysite.com
The displayed url changes to:
www.mysite.com/
But the actual url that the server reads is:
www.mysite.com/?aff=aff1
I'm also going to be adding languages to the mix, so I might even need something like the following:
User links to: aff1.mysite.com
Then I get the language from a cookie {HTTP_COOKIE} lang=([A-Za-z]+)$
If there's nothing in the cookie, the default should be "en"
Then the user gets redirected to aff1.en.mysite.com
Which should then be displayed as: www.mysite.com/en/
but to the server: www.mysite.com/?lang=en&aff=aff1
Please tell me this is possible, and how I can achieve this. I'm very new to rewriting. And I've viewed other questions and tried their solutions, but somehow can't adapt it to exactly what I need.
Also... www.mysite.com shouldn't go to www.mysite.com/aff=www
It should just go to /mysite.com/en/

Answer 1

So, I've spent way more time than I wanted to on this, but finally got something working. Instead of passing the variables in the url, I'm dropping a cookie (which was ultimately what I was doing on the page anyway, but this cuts out a step - and I didn't know that you could drop cookies with the rewrite).
If anyone has a better solution with less lines of code, please feel free to comment or post a new answer.
RewriteEngine On # Turn on the rewriting engine
RewriteCond %{http_host} ^www.example.info [nc] #if url starts with www.example.info
RewriteRule ^(.*)$ http://example.info/$1 [r,nc] #rewrite without the www
RewriteCond %{http_host} ^www.(.*).example.info [nc] #if url starts with www.(aff).example.info
RewriteRule ^(.*)$ http://%1.example.info/$1 [r,nc] #rewrite without the www
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteCond %{http_host} ^(.*)\.example.info [nc] #if subdomain is aff
RewriteRule ^(.*)$ - [co=aff:%1:example.info:7200:/] #drop/update cookie with aff
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteCond %{http_host} ^(.*)\.example.info [nc] #if subdomain is aff
RewriteRule ^(.*)$ http://example.info/$1 [nc,R,L] #rewrite without subdomain