non-standard lookup?

in a workbook of 2 sheets, cell a2 of the second sheet contains a part number. cell b2 needs to return a Yes / No result..
formula needs to lookup whether the part in cell a2 on sheet 2 is contained in a range of cells on sheet 1.. i.e. cell range A2:AK84, column 1 (list of part numbers) and then return the value "Yes" in cell b2 of sheet 2 if the exact part number is found in the list or "No" if the exact part number is not found.
Tried If function and could not get it to work properly, then tried Vlookup but this did not work either.

any ideas? help gratefully received!!