I have looked up some similar problems on these forums so I'm aware that it's not possible to transfer things between xbox live accounts. My problem is slightly different.
Most of the time I've been using my xbox I didn't have it connected to the internet so I've been using a normal profile on the console. My problem is that the email address I usually use is attached to an account I created when I got Dawn of War 2 for my PC. I would prefer to keep the saves and data associated with the profile on my console but I'm not sure how to transfer anything or if it's even possible. My main concern is my Mass Effect data as I'd like to be able to play ME3 on a live account without having to play through again.
I would accept being able to just transfer my save data to my Live account but I get the feeling my only option may be to create a new email address and convert my xbox profile into a Live account.