You are going to have to enter this on Form 8949 with the N code, but I do not believe TurboTax is going to support that entry unless you use Forms Mode.
If you received capital gain distributions as a nominee (that is, they were paid to you but actually belong to someone else), report on Schedule D, line 13, only the amount that belongs to you. Attach a statement showing the full amount you received and the amount you received as a nominee.
