htaccess redirect

Hey,

I’m running into a bit of trouble, and I was hoping I could ask your advice. I’m running an aging blog on a xoops platform using the old XPress module. XPress is wordpress, so I dare ask this question here. And I am going to use my top domain for a new wordpress blog.

My intention is to deprecate the Xoops site and go with a pure wordpress blog. The XPress module is a great module, but it is dead and no one seem to be maintaining it.

Now, I have mirrored the old site as an archive, and i would like to use .htaccess to permanently move all the incoming visitors and links to the subdomain “old”.

The nearly two thousand posts I have on the old blog can all be identified with the following pattern:

[mydomain.com]/modules/wordpress/[some post link]

When someone (or something) clicks on a link on google or the blog portals, they should be permanently redicted to my archive. Anyone that clicks a link without that pattern should be allowed to see the new site.

I’ve read dozens and dozens of htaccess guides, and I think I can reasonably redirect specific files, and specific pages, but how do you redirect according to the above pattern? I can’t seem to find the answer. It will probably be very simple, but so far all my attempts to edit the htaccess results in a 500-error.

This is my last attempt – which gave the 500-error. I’ve got Option +SymLinks on.

RewriteCond %{HTTP_HOST} ^https://[mydomain.com/modules/wordpress/ [OR]
RewriteCond %{HTTP_HOST} ^https://[www.mydomain.com]/modules/wordpress/
RewriteRule ^(.*)$ https://old.[mydomain.com]/modules/wordpress/$ [R=301,NC,L]

Hopefully you all know the answer, and hopefully you could share it with me before I get completely bald from tearing my hair out.

Cheers and thanks in advance.