Bob,

Thanks for the response. Im sorry if I havent made my issue not clear.

In my case the Table array in Lookup formula is to be concatenated (and
not the lookup value).

For example

If Table array has data from A2 through E500, then Col A and Col C
together constitute unique ID.

Also, I have some unique ID's from Z2 through Z10. For each of these 9
Id's I want to do a lookup with Table array and return data from column
E.

So my "incorrect" formula would look something like this.

AA2 = Index(E2:E500,Match(Z2,A2:A500&C2:C500),1)

Basically I want to concatenate the first and third column of my Table
array/Lookup Array.

Regards,
HP
India