.htaccess redirect from root to subdirectory

My website is currently re-directing from http://caspca.org to http://caspca.org/wordpress/ via a simple index.html .js re-direct. This is exactly what I want it to do, but I would prefer to do this the right way, via the .htaccess file, but I’ve been unsuccessful so far.

Following these instructions:
http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory#Pointing_your_home_site.27s_URL_to_a_subdirectory

I changed my original .htaccess file from this:

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

to this (in Step 3 of instructions it says “add”, not “replace”, so that’s what I did):

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www.)?caspca.org$
RewriteRule ^(/)?$ caspca.org/wordpress/blog [L]
RewriteBase /wordpress/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]
</IfModule>

and uploaded it to the root per the instructions. The .htaccess file is the ONLY wordpress file in the root (it didn’t say anything about having an index.php, etc.)

Can anyone tell me how to code the .htaccess file correctly to redirect from caspca.org to caspca.org/wordpress/ ?

Thank you,

John