Before migrating to Ning 1.5 months ago, we had 20,000 pages of content and
many had links to them from third party sites. The vast majority of
those links aren't terribly important, but two are very important for
SEO reasons: http://www.collegerecruiter.com/jobs and http://www.collegerecruiter.com/internship. They were at the top of page
one or two in the Google search results for short tail keyword phrase
searches such as "entry level jobs" and "internships" so we very much
want them back.
If it helps, we have our own servers so we could add a page etc. and
serve it ourselves but I don't think that we can do that unless it is a
third level domain like http://blog.collegerecruiter.com. We're doing
that now for our Wordpress blog.
You can use the URL rewriting tool to do this. Here's some information on it. Please be very careful making changes with the URL rewriting tool. You should be able to add a few of the crucial urls you need and then move them up in the stack to the point where they will take effect.