Including additional information on the Common App

I’ve attended college classes during high school, and the college gave us copies of letters verifying our college work, so we could include it in our college applications. I know I can include additional information under the writing section, but how would I go about submitting this information in a legitimate way, rather than just copying the contents of the letter into the box, or something?

@ihmmfl - if you did a college course for credit, you should have the college send transcript to the college you are applying to. Also, in the education section, there is a spot for you to enter additional information