WP Variables and Remote Updating

Wondering if anyone knows about a plugin to allow for variables in WP, and then to post to those variables remotely.

For instance, I would like to have a variable for “RELEASEDATE” and have someone fill in the variable as “November 21, 2012”
The sentence in the post/page would say: The release date for this manual is “RELEASEDATE”. and it would actually display “The release date for this manual is November 21, 2012”.

So I’d have a list of variables and as those variables are updated, they propagate throughout the site.

And… I’d like to have the ability to have those variables updated by a remote user, maybe someone that doesn’t have regular editor/contributor rights to the site… someone that doesn’t need to log in.

A few months ago I had toyed around with Google Spreadsheets being able to do something like this. I am able to display a specific spreadsheet cell, but am unable to have that cell be fed to my WP site. I have an example somewhere… I think it is bookmarked on my other computer. I’ll edit later.

Any ideas?