RewriteCond to allow access subdirectory

RewriteCond to exclude current rewrites

[bigpill]

So, I'm looking for how to allow access to any file in the www.mysite.com/admin directory. My current .htaccess bring a 404 error.

What I have
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME}!^/admin(/.*)
RewriteRule ^(.*)-p-(.*).html$ product_info.php?products_id=$2&%{QUERY_STRING}
RewriteRule ^(.*)-c-(.*).html$ index.php?cPath=$2&%{QUERY_STRING}
# begin
#RewriteRule ^(.*)-m-(.*).html$ index.php?manufacturers_id=$2&%{QUERY_STRING}
# end
RewriteRule ^(.*)-pi-(.*).html$ popup_image.php?pID=$2&%{QUERY_STRING}
RewriteRule ^(.*)-t-(.*).html$ articles.php?tPath=$2&%{QUERY_STRING}
RewriteRule ^(.*)-a-(.*).html$ article_info.php?articles_id=$2&%{QUERY_STRING}
RewriteRule ^(.*)-pr-(.*).html$ product_reviews.php?products_id=$2&%{QUERY_STRING}
RewriteRule ^(.*)-pri-(.*).html$ product_reviews_info.php?products_id=$2&%{QUERY_STRING}
RewriteRule ^(.*)-i-(.*).html$ information.php?info_id=$2&%{QUERY_STRING}

# begin
RewriteRule ^(.*).html$ index.php?manufacturers_name=$1&%{QUERY_STRING}
RewriteRule ^(.*)-biography.html$ redirect.php?manufacturers_bio=$1&%{QUERY_STRING}

# end

This isn't working. Suggestions?