For publishing, it should be /public_html/subdomainfolder replacing the subdomainfolder with the folder that was created for that sub domain. From the cPanel docs, here is what you need to redirect a subdomain to a page under your account:
You can redirect Internet traffic from a particular subdomain to another location. This is usually used when the web pages that made up the subdomain have been moved to another location.
To add subdomain redirection:
1. Click on the Subdomains button on the home page.
2. Click on the required subdomain from the first drop-down list.
3. Click on the Setup Redirection button.
4. Enter the redirection address in the available field. Make sure that you end the address with a trailing slash (e.g.
http://yourdomain.com/).
5. Click on the Save button.
Hope that helps!