I have been spending a lot of time trying to figure out dynamic chart
ranges and just can't figure it out. I have a chart (scatter plot)
that needs to have the X and Y values of a series linked to the number
of values present, which will be constantly changing. It would also be
nice to have the maximum/minimum scale adjustable as well, for both
axes. the code I am using (below) is causing errors.

Private Sub UpdateChart()
span = Sheets("sheet1").Range("C4").Value * 12
stepsize = Sheets("sheet1").Range("C6").Value * 12
Set CurrentChart = Sheets("sheet2").ChartObjects(1).Chart
CurrentChart.Parent.Width = 450
CurrentChart.Parent.Height = 150

'ActiveChart.SeriesCollection(1).XValues = "=Sheet2!R2C2:R2C" & 2
+_
(span / stepsize) & ""
'ActiveChart.SeriesCollection(1).Values = "=Sheet2!R1C2:R1C" & 2 +
_
(span / stepsize) & ""

ActiveChart.Axes(xlCategory).Select
With ActiveChart.Axes(xlCategory)
.MinimumScale = 0
.MaximumScale = span / stepsize + 1
.MinorUnit = 12
.MajorUnit = 24
.Crosses = 0
End With

' Save chart as GIF
Fname = ThisWorkbook.Path & Application.PathSeparator & "temp.gif"
CurrentChart.Export Filename:=Fname, FilterName:="GIF"

' Show the chart
Image3.Picture = LoadPicture(Fname)
End Sub