One way:

=VLOOKUP(A1,[Workbook2]Sheet1!$A:$IV,123,FALSE)

It's easiest to create the link with the workbook open, as shown above.
Otherwise, include the path in your reference.

In article ,
el_grimley
wrote:

Is it possible to refrence an entire worksheet from another workbook
(which is unopened) so that I can use its cells for a Vlookup?

Thanks

Graham