I'm not sure you can get to it using Mobile me? (I Dont use it)
If not, then you can use a free FTP client to access the pages & if for some reason that does not work, you could always try
YummyFTP as an FTP client. Its really cheap & has worked great for me.
Also, but not sure. After saving your site in iWeb, it saves to a folder where you can also access your HTML & add it in there before you upload it to your host. Maybe? Never tried it, but dont see why it wouldn't work.