Change Permalinks for a certain Category

I use the following permalink strukture:

/%year%/%monthnum%/%day%/%postname%/

Standard .htaccess:

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Logical result:

http://www.mydomain.com/yy/mm/dd/post-name/

Now, I have one category, where I would like to set the permalinks to:

http://www.mydomain.com/post-name/

or alternative

http://www.mydomain.com/category-name/post-name/

The rest should stay as is.

Any .htacces pros here?