Is there any sort of mod command in Apache the allows me to specify a list of directories to be searched when looking for a certain web document?

Here's what I am attempting to do:

I have a default web document located in (example) /document_root/defaultDirectory/

I may wish to override this document by storing a revised version of it in (example) /document_root/overrideDirectory/

So my question is, without having to write the script to perform an include() using the document in the 'overrideDirectory' if it exists, otherwise including it from the 'defaultDirectory'.

Is there any apache command I can put into my .htaccess file that tells the server to look in the 'overrideDirectory' for the document first and if the document does not exist, get it from the 'defaultDirectory'?

Thanks