Since SS is not able to replicate the original URI structure, is it possible then to set up redirects in the .htaccess file that would be successful?

eg: Redirect 301 www.domain.com/subdirectory/oldpage.html http://www.domain.com/newpage/

yes:

Redirect 301 /subdirectory/oldpage.html http://www.domain.com/newpage/

I have set the redirects up in the .htaccess file before Silverstripe's block. On clicking links to the older URIs, I get the new URI with a ?url=/oldURI.html.

Should the redirects be after the Silverstripe block? What is the best way to avoid the ?url=/oldURI.html ?

Thanks very much to DesignCity and simon_w who helped me fix my problem on IRC :)))))

Please share your solution with the forum... Someone else might need this as well..

Thanks

At the top of .htaccess (before the SilverStripe block) place this:
RewriteRule Directory/File.html newURI/ [R=301,L]

Just to expand on the previous post:
If you set up the following (using my own site as the example):
RewriteRule social/maternity/ http://nfaw.org/paid-maternity-leave/ [R=301,L]
RewriteRule social/ http://nfaw.org/women-s-social-policy/ [R=301,L]

The redirects seem to work as expected. The most specific one is triggered first, followed by the more general. You can get users to the most popular entry points directly, while for other pages, they at least land in the right part of the site.

Your web stats program should identify the most common entry points to help with this process.