Yes, copy those and rename (make sure the renaming is done properly). Modify to meet Your needs.
And do not forget to add a new menu entry in the administration, so modify these files as well:
admin/controller/common/header.php
- add new text and action linkadmin/language/english/common/header.php
- add new entry translationadmin/view/template/common/header.tpl
- add new entry
That should be it. And of course, do not forget to modify the footer part of Your store ;-)