Is there a way using php or htaccess to prevent access to a certain part of an url

[Pengu]

For example a user can not access http://example.com/here but can access anything with more added. An example would be http://example.com/her?action=blah blah.The point of this is to prevent access to an file by visiting the page directly, however allow the file to be use with more actions/links added.