I know that I cannot use SUMif when linking to closed workbooks. I have the
following formula which only works when the workbook is open:

=SUMIF('C:\Documents and Settings\Kärsälä\My Documents\Farm Documents\Tax
Documents and Spreadsheets\[2007 draft Tax Documents.xls]Maa.
Tili'!$C$6:$C$40,"="&'Maa. Tulot'!C13,'C:\Documents and Settings\Kärsälä\My
Documents\Farm Documents\Tax Documents and Spreadsheets\[2007 draft Tax
Documents.xls]Maa. Tili'!$D$6:$I$40)

What could I do to make this work? I have tried both SUMproduct and SUM(if
but excel returned errors both times, presumably because my typing is so poor.

In case there is an easier way what I am trying to achieve is to match the
text in the range on my summary sheet to the same text in the range in the
annual sheets. When a match is found the adjacent value should be returned.

Thanks in advance for your help.