Here is the code to select every other row in a selection. The code could be made more generic and prompt the user for how many rows to skip between selection.
	Sub SelectEverySecond()
    Dim rwStart As Integer, rwEnd As Integer, rwCur As Integer
    Dim colStart As Integer, colEnd As Integer
    Dim r1 As Range, r2 As Range, rFinal As Range
rwStart = Selection.Row
    rwEnd = rwStart + Selection.Rows.Count - 1
    colStart = Selection.Column
    colEnd = colStart + Selection.Columns.Count - 1
rwCur = rwStart
    Set rFinal = Range(Cells(rwCur, colStart), Cells(rwCur, colEnd))
    rwCur = rwCur + 2
While rwCur <= rwEnd
    Set r2 = Range(Cells(rwCur, colStart), Cells(rwCur, colEnd))
    Set rFinal = Union(rFinal, r2)
    rwCur = rwCur + 2
    Wend
    rFinal.Select
End Sub
 
Then you can run this code to create the chart of the new selection:
	Sub ChartIt()
    Dim strName As String
strName = ActiveSheet.Name
Charts.Add
    ActiveChart.ChartType = xlColumnClustered
    ActiveChart.Location Where:=xlLocationAsObject, Name:=strName
End Sub
 
To test the code, put chart labels in column A and chart values in column B. Select all the data like you would when creating a chart. Run the first macro then the second. You should now have a chart with every other point charted.
Enjoy.