Have dates in column S, and quantities shipped in columns M & N.

Looking for sither a SUMIF OR SUMPRODUCT formula which will give us
the year to date shipments in another workbook.

This one doesn't do it. . .Produces #VALUE .

=SUMPRODUCT(--(YEAR('[CST100.xls]Summary'!$S$8:$S
$800)=YEAR(2008)),'[CS0107.xls]Summary'!$M$8:$N$800)

Any ideas?

Pierre