It doesn’t really help. Law school admissions is pretty much based solely on GPA and LSAT scores. They don’t bother with what school you went to and what not. If anything, I’m sure Cornell has a great alumni network so connections maybe what you get out of going there for undergrad.
If (note correction of typo) you were (note grammar) to go to Cornell, it would affect (sp) your admission to Harvard Law in a positive way as they are both Ivies.