Match and lookup or better

Hi to all:

I have a spreadsheet with two worksheet:

Data & Helper List

Data:
Market COID
empty cell 10076
empty cell 24548

Helper list:

Market COID
Broward 24548
Dade 10076

What is the most efficient and fast formula that would fill in the
Empty cells from the Helper List I created.


Thank you excel community. This week what would I have done with out you. Been very helpfull.