Rewrite for folder

Is it possible to have ISPConfig to rewrite folder as subdomain?

Example, I want that:

http://www.yourdomain.tld/webmail

is rewritten to

http://webmail.yourdomain.tld

I want that the adress still remain webmail.yourdomain.tld...

 

Thank you till, I'm a newbie with those stuff, can you please help me on writing the directives?

 

Take a look here: http://www.stevenhargrove.com/redirect-web-pages/
http://httpd.apache.org/docs/2.0/misc/rewriteguide.html