.htaccess – Subdomain Rewrite Rule

Hey!

I’m new to web design/servers, so please pardon me if this post lacks correct jargon.

I’m trying to set up my blog so that it works with a subdomain. The blog is located at marein.org/words, and works fine there. What I’ve also got working is words.marein.org. That seems to redirect/rewrite/go to the first URL.

However, what I haven’t got working yet is pages other than the index. For example, I’d like for words.marein.org/newstart to lead to the same as marein.org/words/newstart (a post on the blog). But at the moment, that first link just leads to a 500 Internal Server Error page.

Someone already gave me this .htaccess code:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^words\.marein\.org$ [NC]
RewriteRule ^(.*)$ http://marein.org/words/$1 [R=301,L]

Which at first didn’t work, until I removed the code from .htaccess that WordPress told me to put there. To be clear, I mean this code:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /words/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /words/index.php [L]
</IfModule>

Removing that allowed the other code to do its work, but broke WordPress.

So, my question is, is there a way to combine these two codes so that WordPress works and the subdomain links are rewritten correctly, or perhaps another solution?

Thanks in advance!