I reference a report of data by code in workbook W1.xlsx produced by another
workgroup, something like this. Note that the codes are in random order.

A B C D
1 code Jan-09 Feb-09 Mar-09
2 c 200 150 300
3 a 300 310 315
4 b 225 215 210

I need to produce a report each month in a separate workbook that will
provide a YTD sum by code. The desired month is entered in B1, e.g. Feb-09.
I need a formula for cell B2 which I can copy down column B for the other
codes that will result in the YTD sum of each code. So the result of B2 in
Jan-09 would be 200, in Feb-09 350, and in Mar-09 650.

A B
1 code Feb-09
2 a
3 b
4 c

Thank you.