Conditional Sum based on independent evaluation

[analysis headache]

I am trying to figure out how to sum certain cells in a row that correspond
to a Date in the same column. For example.
A B C D E
F G
1 DATE 1/1/2008 2/1/2008 3/1/2008 4/1/2008 5/1/2008
2 VENDOR 3/1/2008 10 20 30 40 50

In this example. I want to sum all the numbers in row 2 which have a date
greater then or equal to the date in cell b2.

 

[smartin]

I am trying to figure out how to sum certain cells in a row that correspond
to a Date in the same column. For example.
A B C D E
F G
1 DATE 1/1/2008 2/1/2008 3/1/2008 4/1/2008 5/1/2008
2 VENDOR 3/1/2008 10 20 30 40 50

In this example. I want to sum all the numbers in row 2 which have a date
greater then or equal to the date in cell b2.

Not sure how your data is laid out exactly, but if it looks like this:

A B C D E F G H
1 DATE 01/01 02/01 03/01 04/01 05/01
2 VENDOR 03/01 10 20 30 40 50 120

H2 is =SUMIF(C1:G1,">="&B2,C2:G2)