SUMPRODUCT and #VALUE error

Hey! Ive read up some of the posts about this and realise that I can use SUMPRODUCT to link workbooks even when they are closed so that it doesnt give the #VALUE error, and I have tried it but Im having a little trouble and its still giving me the value error...

Im linking two work books just to draw some accounting numbers from one to the other but the one has to remain closed. originally I was using the sumif and it looked like this =SUMIF([BGP2009data.xls]MBGPTM!$A:$A,$A5,[BGP2009data.xls]MBGPTM!$T:$T)

What I was doing here is that in the second workbook Im checking that if the values in column A match up with the values in the first workbook, of they do then it must draw the number from the corresponding cell in column T into the second workbook...

I tried typing in =SUMPRODUCT(- -('[BGP2009data.xls]MBGPTM'!$A:$A,$A5),'[BGP2009data.xls]MBGPTM'!$T:$T)

Im still pretty new at excel so Im not sure if its just a typin error, but it would be awesome if you could help me out
Thanks!

Don't know if that gap between two -s is just a typo here but that shouldn't be there.......and you need an = to compare against A5......and you can't use whole columns for SUMPRODUCT in Excel 2003, you need a specific range, e.g. for rows 2 to 1000

=SUMPRODUCT(--('[BGP2009data.xls]MBGPTM'!$A2:$A1000=$A5),'[BGP2009data.xls]MBGPTM'!$T2:$T1000)

changes ranges as required

okay thanks...ill give it a try and see if it works