mod_rewrite .htaccess subdomain redirect - regex

Question

I spend the last 2 days searching and learning about .htaccess to redirect all subdomains to a user folder
without changing the url, but i keep having 3 little problems. I really would appreciate some help
problem 1)
If i go to http://www.example.com/users/foo it automatically redirect
the url to http://foo.example.com/ but if i go to http://www.example.com/users/foo/dashboard.php
it does nothing, instead of redirecting to http://foo.example.com/dashboard.php
this is the code i use:
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /users/(.+)/\ HTTP/
RewriteRule ^users/([^/]+)/(.*)$ http://$1.example.com/$2 [R=301,L]
problem 2)
if i go to http://foo.example.com/dashboard.php
it gets its information from http://www.example.com/users/foo/dashboard.php
but if i type foo.example.com in the address bar (in firefox) it (sometimes) automatically redirect
to www.foo.example.com, can i prevent the www prefix?
this is the code
RewriteCond %{REQUEST_URI} !^/users/
RewriteCond %{HTTP_HOST} !^www\.example\.com [NC]
RewriteCond %{HTTP_HOST} ([^.]+)\.example\.com
RewriteRule (.*) /users/%1/$1 [L]
problem 3)
the campaign website is locaded in the folder http://www.example.com/website but should be
visible on the url http://www.example.com/ (like i get the information from http://www.example.com/users/foo
on the url http://foo.example.com/).

Answer 1

About problem one I would just check the host:
RewriteCond %{HTTP_HOST} ^www.domain.com$
RewriteRule ^users/([^/]+)/(.*)$ http://$1.domain.com/$2 [R=301,L]
About problem second this is a modified rule which I got from the drupal .htaccess file:
# remove www prefix
RewriteCond %{HTTP_HOST} ^www\.(.+)\.domain\.com$ [NC]
RewriteRule ^ http://%1%.domain.com{REQUEST_URI} [L,R=301]
# redirect to the subdirectory
RewriteCond %{HTTP_HOST} !^www\.(.+)\.domain\.com$ [NC]
RewriteCond %{HTTP_HOST} ^(.+)\.domain\.com$ [NC]
RewriteRule ^ user/%1%{REQUEST_URI} [L,R=301]
About your third problem check this one here:
RewriteCond %{HTTP_HOST} ^www.domain.com$
RewriteRule ^(.*)$ website/$1 [R=301,L]