Content Locker Plugin Question

Hello,

I am looking for a content locker wordpress plugin whereby the site visitor has to type in a code that unlocks a paragraph or two of text. People with the code can see the additional content, those that dont have the code cannot. I want to be able to change the required code needed on a daily basis to unlock different parts of a blog.

This maybe a stupid question but I know nothing about content locking just that when I see this subject people always talk about filling out questionnaires, thats not what I am looking for.

Any help with this greatly appreciated.

Really appreciate if anyone can chime in here, does this exist? yes/no.

Warm regards,

Anthony