I found a fast way of utilising VLOOKUP when having huge amount of data (I'm looking at 1,000,000 rows of data looking up another table of 200,000 to 500,000 rows (& 15 columns, if that as any bearing).
I used the following:
=IF(VLOOKUP(id,data,1,TRUE)=id, VLOOKUP(id,data,col,TRUE), NA())
This...