Changing “DateAdded” by folder?

I have a directive in my advanced settings of:

Code:
<videolibrary>
  <dateadded>0</dateadded>
</videolibrary>

…Which means that a file’s age is calculated based on the current date rather than the file date, so that a “new” file appears on the recently added movies list even if it the file itself is a year old.

However, sometimes I sort my files into other directories after a while to make my collection more manageable. Doing this causes the library entry to be removed and recreated, which I know is unavoidable, but due to my settings change results in the file popping to the top of the list again.

Is there any way to set the <dateadded> setting to “1” but only for files stored in a particular location, like perhaps a subdirectory off the main one of /watched/ ?

Also one other slight annoyance is if I refresh a movie’s entry, its add date is also changed to the current date, popping it to the top again.