Function to compare lists...

I have two lists as such:
First Name, Last Name, Position, Company

I would like a function/macro that will compare the two lists and create a third list that has all the rows that were in the first list but not in the second list. But, I only want the comparison to be done on First Name and Last Name.

So Sheet1 has:
FName1, LName1, Pos1, Co1
FName2, LName2, Pos2, Co2
FName3, LName3, Pos1, Co3
FName4, LName4, Pos1, Co4

Sheet2 Has:
FName1, LName1, Pos1, Co1
FName4, LName4, Pos1, Co4
FName5, LName5, Pos5, Co5
FName6, LName6, Pos6, Co6

I would like a third sheet created that has:
FName2, LName2, Pos2, Co2
FName3, LName3, Pos1, Co3

I'm using Excel Mac 2011.

Thanks!