[Plugin: WP No Category Base] subcategory permalink only

hiii
thanks for the plugin.
with this plugin, I could use the post name as http://www.sitename.com/post_name and also could make http://www.sitename.com/parent/subcategory url.
but how can I use the subcategory only without the parent so I get:
http://www.sitename.com/subcategory ?

http://ww.wp.xz.cn/extend/plugins/wp-no-category-base/