heh, obviously.
Redirect /folder will redirect all requests, including /folder/folder2
You could redirect using mod_rewrite
Code:
RewriteEngine On
RewriteCond %{REQUEST_URI} !^/folder/folder2.*$ [NC]
RewriteCond %{REQUEST_URI} ^/folder/.*$ [NC]
RewriteRule ^(.*) http://www.domain.com/folder/folder2/$1 [R,L]