Pointing subdomains to a "directory" - apache

Question

I have two questions regarding pointing subdomains to a directory:
Currently I run local, but I can run my site on a fake domain i have set up (with hosts file), its called mysite.com. How can i (by server settings?) do so All subdomains will point to / ? Example anders.mysite.com should show mysite.com and asdassdd.mysite.com also.
Maybe 1. is not necessary, but how do i by htaccess point anders.mysite.com to mysite.com/anders ? Important notice is that should not redirect.
Why i thought of 1. is because I do not want to specify anywhere in the htaccess or any apache/domain setting, what the subdomain are, since this will be dynamic (created by logged in users in my webapplication)
Currently the users can use mysite.com/anders/ which is a URI they have created, and not a real directory. In the Kohana bootstrap I am then grabbing the URI and showing the relevant user page.
I am using Kohana MVC framework and have this in my htaccess:
# Turn on URL rewriting
RewriteEngine On
# Installation directory
RewriteBase /
# Protect hidden files from being viewed
<Files .*>
Order Deny,Allow
Deny From All
</Files>
# Protect application and system files from being viewed
RewriteRule ^(?:application|modules|system)\b.* index.php/$0 [L]
# Allow any files or directories that exist to be displayed directly
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# Rewrite all other URLs to index.php/URL
RewriteRule .* index.php/$0 [PT]
Any help appreciated!

Answer 1

For 1, in your vhost just add a ServerAlias:
ServerAlias *.mysite.com
Then any subdomain (www included) will get pointed to the same document root.
If you want to put subdomains in their own directory (and since you have access to server config), you can use mod_vhost_alias and the VirtualDocumentRoot directive:
VirtualDocumentRoot /path/to/your/htdocs/%1
So if you request blah.mysite.com, you'll end up in /path/to/your/htdocs/blah as the doc root.
If it's a matter of you needing directory names of non-existent directories in the URI so that Kohana can route them, you'll need to make sure you have mod_proxy loaded:
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteCond %{HTTP_HOST} ^([^.]+)\.
RewriteCond %{REQUEST_URI} !^/%1/
RewriteRule ^(.*)$ /%1/$1 [L,P]
To proxy the request back to Kohana with the right URI.

Answer 2

how do i by htaccess point anders.mysite.com to mysite.com/anders ? Important notice is that should not redirect.
You can use this rule:
RewriteCond %{HTTP_HOST}:%{REQUEST_URI} ^([^.]+)\.[^:]+:(?!/\1/).*$
RewriteRule ^ /%1%{REQUEST_URI} [L]