Select every other cell in a row for a formula

[cdpar]

Hi,

I have a row of numbers with more than 100 cells. I need to "Select" every other cell to use in a formula.

Example: SUM(A1+A3+A5+A7 ... GA1+GA3)

How can I automatically have Excel give me all of the cell addresses for every other cell in the row?

The number of cells in the row changes from week to week so I have to modify the resulting formula each week.

Thank you!

 

[Fluff]

If you are simply trying to sum the row you can use this
=SUM(IF(ISODD(COLUMN($A1:$EZ1)),$A$1:$EZ$1))
Just change the values in red to a column that you don't think will ever be exceeded.

 

[cdpar]

Great, Thank you for all of your help!

 

[Fluff]

You're welcome

 

[ravishankar]

paste the following codes to right click on the sheet name > view code > paste

Private Sub Worksheet_Change(ByVal Target As Range)
Dim x As Integer, a As Integer, total As Integer
    If Target.Address = "$A$150" Then
    x = Cells(1, Columns.Count).End(xlToLeft).Column
    total = 0
            For a = 1 To x Step 2
            total = total + Cells(1, a)
            Next a
        Cells(150, 1) = total
    End If
MsgBox "The total of odd columns from " & x & " columns is " & Cells(150, 1)
End Sub

when you click on cell 150 it recalculates and sum of odd columns is displayed with a message. I did experience some problems I will try to solve it.