Code:
=IF('Combined Data'!K2>=$E$2,IF(ISNA(VLOOKUP('Combined Data'!D2,'Combined Data'!$D$2:$D$100,1,FALSE)),#N/A,VLOOKUP('Combined Data'!D2,'Combined Data'!$D$2:$D$100,1,FALSE)),#N/A)
Better yet, does it look correct.
I guess the only thing that matters, is that it works.