Trouble submitting Dartmouth peer recommendation?

Hello all! My friend asked my write a peer recommendation for him to Dartmouth, so I wrote a letter about his strengths and qualities, and I specifically addressed how I think he would be a good fit for Dartmouth. However, when I went to send the letter in on my CommonApp recommender account, it said that my letter would be sent to ALL of the colleges he is applying for, even though he only needs Dartmouth. Is there any way I can send it only to Dartmouth? I think the specifics and concrete examples in my letter will help him get in, opposed to a more generalized letter. Thank you!!!