I tried using a letter I recieved regarding graduation and my transcript saying I have 113 out of the 120 credits needed to graduate. I was told I needed something a little more specific. I went to my grad office, and they told me they wouldn't do it. I then went to my enrollment services building(where you register for classes) and they were able to give me a "letter of intent". It's a predrafted letter with blanks for the name and date, that says if you don't screw up, you're scheduled to graduate at a certain time. All they did was look in the system and checked when I was registered to graduate(May), and filled the form out. See if you can grab one of these.
HTH
Craig