If my domain is "mydomain.com" and if I want to use subdomain.mydomain.com with my x10hosting account, how can I do that? How do I point a subdomain from my godaddy account to my x10 hosting account?
Create an A record at your domain account for that subdomain. The IP will be the IP for your hosting server, you can find that info in your cPanel. Then add your subdomain to your account as main domain, parked domain, or addon domain.