Hi there,
Here is a link to information on accomplishing the redirect you are attempting to do:
http://www.widexl.com/tutorials/mod_rewrite.html#redirect_domain_dirBased on the information you provided, it should look something like this in your .htaccess file:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^domain.info$
RewriteCond %{REQUEST_URI} !^/folder/
RewriteRule ^(.*)$ /folder/$1
Or if the 'folder' you are referring to is in the public_html folder, you can simply add the domain to your account as an addon domain, using the following details in cPanel > Addon domains:
Domain name: domain.info
Username/subdomain name/folder: folder
Password: (password of your choice)
Hope this helps.