This blog post explains the details of work with htaccess file.

Details: Please note that htaccess management will pick up your live/current .htaccess file within the directory you select. Your public directory (/htdocs)is selected by default.

Setting rules on this page will simply add to your existing .htaccess file. You also have the ability to add custom code. Please also not that any htaccess file above a set of directories will apply to that directory and all subdirectories. If you create an htaccess file under the root of your domain, which is /htdocs, then those rules will apply to every subdirectory under /htdocs.

This entry explained how to work with htaccess file.