Below is a rewrite-rule for the domain 2q11.com, making it so that
2q11.com/foo is rewritten as www.2q11.com/serve.cgi?foo
<VirtualHost *:80>
DocumentRoot /home/mfest/web/2q11/
ServerName www.2q11.com
RewriteEngine on
RewriteLogLevel 1
RedirectPermanent 2q11.com http://www.2q11.com
RewriteCond %{REQUEST_URI} ^/([^/][^/]*)(/|$)
RewriteRule ^/(.*) http://www.2q11.com/serve.cgi?$1 [L]

Try out www.2q11.com/test as an example. 

Here's the problem: I make it so that in addition foo.2q11.com is
rewritten as www.2q11.com/serve.cgi?foo-- with the exception of foo
being "www" or "".

I tried putting the following both in the core of my httpd.conf
configuration and inside the virtual container for 2q11.com , but each
time it did not work:

RewriteCond %{HTTP_HOST} !www.2q11.com [NC]
RewriteCond %{HTTP_HOST} (.*).2q11.com [NC]
RewriteRule ^http://(.*).2q11.com/$ http://www.2q11.com/serve.cgi?$1 [L]

What's the solution for this problem? Thank you.