How to handle 301 redirects, and directory change…

Hi folks,
In January I started migrating from Joomla to WP.
I eventually managed to migrate all the articles over and maintain the unique IDs of them.

I was getting help at the time via this post. But I dropped the ball because I ran out of time during my holiday. I am working on it again, and need to now figure out the 301 redirects. I am starting a new post to focus in on that part of my question/challenge.

Here’s the back ground info

• Joomla was installed in www.domain.com/site/
• WordPress has been installed in domain.com/wordpress/
• All Joomla articles were migrated to WordPress installation, and post IDs were maintained.
• Joomla URI permalink structure for articles is: www.domain.com/site/YYYYMMDD###/...

**e.g.** www.domain.com/site/20110623398/articles/category-slug/article-slug.html

The ### is the unique ID of the article on Joomla (aka post ID).

• The posts in WordPress have the same unique ID. Thus www.domain.com/site/20110623398/articles/category-slug/article-slug.html can be redirected to domain.com/?p=398
• There are a few other URI structures I’ll need to handle. But I will address that once I have the redirection of the articles figured out.

**WHAT I AM TRYING TO ACHIEVE**
Here’s what I am trying to figure out. So far to no avail.

1. Is it going to work best if I move the WP install to /site/ (after renaming the joomla install directory to something else).
2. I wish to know hot to set up the .htaccess file(s) so that all incoming links to joomla articles have the unique ID extracted and then redirect to /?p=UID (as a 301 redirect)?
3. How do I do this in such a way that the site will always use or display domain.com/ as the home directory (with and without the www), whilst keeping the site located in /wordpress (or in /site, if that works better for the redirects – which I suspect it will).
   I don’t, however, want the site to ever load up and show a /wordpress/post-name-etc/ type URI (or /site/post-name-etc/ URI). Meaning I want the /wordpress/ or /site/ part to always be removed from the end user point of view (including search engines).

   I believe the .htaccess file is also used for this.

4. Along with many other sites and posts, I have read the info at Giving WordPress It’s Own Directory on the WordPress Codex.

Point #4 on that article says, “Copy (NOT MOVE!) the index.php and .htaccess files from the WordPress directory into the root directory of your site (Blog address).”, but I have a .htaccess file in the root already, and it has lots of code in it.

I have tried following those instructions, but I end up with just the theme loading up, and no content.

—

As mentioned above, I suspect it may be best if I move the wordpress site to domain.com/site (and change it’s configuration file home directory settings accordingly). But I am not sure.

So far I’ve tried a few things, but I am not sure it’s worth detailing it all here and now.

I’d really like to get this resolved.