Selective sum

[Constant]

This is a simplified example. In reality I have several hundred columns and rows.

The problem is simple: for each row (day) I want to add separately the negative numbers (in column Z) and all the positive numbers (in column Y) ignoring the first column of each budget (giving the number of operation this day). So only adding column F,H,J,L,N,P,R,T,V,X etc…

Is it possible with an excel function?

Best regards and thanks in advance.

 

[Luke M]

Here's a solution using the SUMPRODUCT function.

 

[Constant]

Thank You very much for your quick reply. It will save me a lot of time.
Greating from Belgium - Flanders near Brugge.