nested If Sumproduct #VALUE! problem

[Sharon]

Hello - I tried to be as brief & detailed as possible. I look forward to
your replies.

I created below formula with SUMIF which returns correct value of 1.56%
(based on matching dates). Because the formula refers to a closed workbook I
edited with SUMPRODUCT.

SUMPRODUCT is returning " " .
The evaluation tool indicates the IF statement to be true due to no data in
the closed wbk cell C6 ....the empty cell equates to 0=#VALUE!

closed wbk row 6 may either be empty, contain a date, or contain text
my worksheet has dates on row 262
when the dates match, I want the calculation, otherwise I want " ".

Also, how would I edit formula to return the sum of multiple rows ie; 44,
46, 47.

=IF(ISERROR(IF(SUMPRODUCT('Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$6:$AV$6,BD262,'Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$5:$AV$5)=" ","
",SUMPRODUCT('Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$6:$AV$6,BD262,'Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$45:$AV$45)*-1)),"
",IF(SUMPRODUCT('Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$6:$AV$6,BD262,'Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$5:$AV$5)=" ","
",SUMPRODUCT('Q:\Finance\Forecast\2007\10+2\Debt
Files\[2008-1.xls]Forecast'!$A$6:$AV$6,BD262,'Q:\Finance\Forecast\2007\10+2\Debt Files\[2008-1.xls]Forecast'!$A$45:$AV$45)*-1))