Is this for free hosting? Our domain name linking service on free hosting (assuming you are talking about that) does not support subdomains. So lets say you have account.t35.com and you requested yourdomain.com to be linked to it. Yourdomain.com, yourdomain.com/files.html, yourdomain.com/folder/, etc.. will all work. But you can't add or use folder.yourdomain.com and expect it to work on the account.t35.com you have it linked to, because in effect you would be trying to use folder.account.t35.com, which is not possible.

The second scenerio, if you are trying to submit a domain name linking request for a SUBDOMAIN, that won't work at all. It's only possible to link a domain name to your free hosting account, not a subdomain you host elsewhere (since you can't set name servers for a subdomain).