将文件夹子域重定向到htaccess中的subdomain.domain.com

I have a domain name domain.com and some folders inside it. When i am accessing the folders inside this domain i can access the folder like this.

http://www.domain.com/folder

I want to convert this url with htaccess to

http://www.folder.domain.com

I would like to have similar urls for all folders so its a wildcard entry. Please tell me how can it be done with htaccess.

RewriteEngine on
RewriteCond %{HTTP_HOST} ^domain.com
RewriteRule ^(.*)$ http://subdomains.domain.com/$1 [L,NC,QSA]

You can use:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^(?:www\.)?domain\.com [NC]
RewriteRule ^([^/]+)(/.*)?$ http://www.$1.domain.com$2 [R=301,L,NC]

RewriteCond %{HTTP_HOST} ^www\.(.+)\.domain\.com [NC]
RewriteRule ^(.*)$ /%1/$1 [L]

To redirect requests to www.example.com/blog to blog.example.com, try this :

RewriteEngine on

RewriteCond %{HTTP_HOST} ^(www\.)?example\.com$
RewriteRule ^blog/(.*)$ http://blog.example.com/$1 [L,QSA,R=301]

RewriteCond %{HTTP_HOST} ^blog\.example\.com$
RewriteCond %{REQUEST_URI} !^blog/
RewriteRule ^(.*)$ /blog/$1 [L,QSA]

For other you have to set dynamic name and pass as parameter, for simple blog you can take help of this question.