I currently have one domain for one site under Basic Windows Hosting account. My domain on this site is www.mydomain1.com I have another domain, www.mydomain2.com and this domain is now hosting somewhere else for another website but I like to create a subdomain for this mydomain2.com and this subdomain will be demo.mydomain2.com and pointing this subdomain to WinHost under mydomain1.com But the problem I am facing is how do I point demo.mydomain2.com to a subdirectory at www.mydomain1.com? Please help
Check out the Knowledge Base article, How to host multiple domains in one account site. That should tell you everything you need to know.