Okay... I'm not exactly sure if what I'm trying to do is possible...

Lets say I have a website at:
website.com/dir/

Then I also have a sub directory at:
website.com/dir/portal/

What I want to do... if someone goes to /dir/, I want them to get forwarded to /dir/portal/

Then if someone goes to /dir/forum/, I want them forwarded to /dir/

So the route would be:
/dir/ => /dir/portal/
/dir/forum/ => /dir/



This is my current htaccess...
Code:
## Expires
<ifModule mod_expires.c>
	ExpiresActive On
	ExpiresDefault "access plus 1 seconds"
	ExpiresByType text/html "access plus 1 seconds"
	ExpiresByType image/gif "access plus 3456000 seconds"
	ExpiresByType image/jpeg "access plus 3456000 seconds"
	ExpiresByType image/png "access plus 3456000 seconds"
	ExpiresByType text/css "access plus 3456000 seconds"
	ExpiresByType text/javascript "access plus 3456000 seconds"
	ExpiresByType application/javascript "access plus 3456000 seconds"
	ExpiresByType application/x-javascript "access plus 3456000 seconds"
</ifModule>

## Compression
<ifmodule mod_headers.c>
	<ifmodule mod_deflate.c>
		AddOutputFilterByType DEFLATE text/html text/css text/xml application/x-javascript
		BrowserMatch ^Mozilla/4 gzip-only-text/html
		BrowserMatch ^Mozilla/4\.0[678] no-gzip
		BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
	</ifmodule>
</ifmodule>

## Rewrites
<IfModule mod_rewrite.c>
	RewriteEngine On

	RewriteCond %{REQUEST_FILENAME} -f [OR]
	RewriteCond %{REQUEST_FILENAME} -l [OR]
	RewriteCond %{REQUEST_FILENAME} -d
	RewriteRule ^.*$ - [NC,L]
	RewriteRule ^(data|js|styles|install) - [NC,L]
	RewriteRule ^.*$ index.php [NC,L]
</IfModule>