Can a SUMPRODUCT array formula be used across multiple worksheets?
 

Hi -

I have a workbook with 32 worksheets (Summary and 1-31) ... all sheets
are formatted the same way, with names in column A and then data-
values in B:L. The list of names on the Summary Sheet is all-
inclusive; however, these names may or may not appear on sheets 1-31.

Of course, the Summary should add up the values (per name) on sheets
1-31, and handle the fact that a) the name may not exist on a specific
sheet, and b) that the value on the sheet may be an error (#N/A).

Here's what I have so far, which doesn't work:
=SUM(IF(ISNUMBER(VLOOKUP($A28,'1:31'!$A$27:$L$395, 3,FALSE)),
0,VLOOKUP($A28,'1:31'!$A$27:$L$395,3,FALSE)))

How can this formula be modified to sum appropriately? or, is there
another formula that would work better?

TIA<
ray