Intercept 404s for pages in certain path
Use the Match Redirect module to redirect specific pages that matches urls.

Summary of drupal project page :

This module provides redirecting based on path patterns with wildcards. This functions much like how block page visibility works. You specify a pattern like "old-blog/*" and a target like "new-blog" and all pages under old-blog will be redirected to the page new-blog.

Features
Pattern matching allowing wildcard redirects
Redirect code choice (301, 302, etc)
Filters out existing pages so they won't be redirected (unless overridden)
Loop protection (no chaining redirects allowed)