An entire folder can be redirected rather easily. For example, to redirect domain.tld/oldfolder/file.html to domain.tld/newfolder/file.html, you would use the following code in your .htaccess file:
I am not sure, however, if that will properly redirect query strings as well. If it doesn't, you may need to use mod_rewrite.

__________________
The best way to learn anything, is to question everything.