This might not help you get specifically into UMDNJ, but one way I've found to get shadowing opportunities is to speak with your college's alumni association. Most keep a database of people who are in different fields who are willing to talk to students and alum about their work. When I was deciding whether or not to go back for pre-med, I contacted my school's alumni office, and got a list of alumni physicians in my area. Then I wrote each of them asking if I could shadow them sometime. I got quite a few responses this way.
If your heart is set on a particular place, I would say just call them up and see if they have any opportunities. Some hospitals do allow students to shadow docs, others have much stricter policies. It can't hurt to ask.