How to set a virtual host in httpd-vhosts.conf with a specific redirect in .htaccess?

Question

Apache HTTP Server

Content of .htaccess
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* localhost/site1/index.php [L]
What should be the content of
DocumentRoot "C:/xampp/htdocs/... .ServerName
tinys