Server :: Sub Domain Configuration In Apache ( On Debian )?

i have several sites hosted on one machine (Apache 2.2 on Debian). They are configured at /etc/apache2/sites-available/ with this configuration (part of it):

RewriteMap lowercase int:tolower
RewriteRule ^(.+) ${lowercase:%{SERVER_NAME}}$1 [C]
RewriteRule ^(([^./]+.)?site1.com)/(.*) /www/site1.com/www/root/$3 [L]
RewriteRule ^(([^./]+.)?site2.com)/(.*) /www/site2.com/www/root/$3 [L]
RewriteRule ^(([^./]+.)?site3.com)/(.*) /www/site3.com/www/root/$3 [L]
RewriteRule ^(([^./]+.)?site4.com)/(.*) /www/site4.com/www/root/$3 [L]

[Code]...