Referencing a chart sheet
 

I'm trying to adapt some code (from Jon Peltier's website) to scale chart
axes based on cell contents. I can get the code to work for charts embedded
in the active worksheet and other worksheets, but I can't figure out how to
reference a chart that is on it's own sheet. How is this done?

Here is the type of code I'm working with:

ActiveSheet.ChartObjects("Chart 1").Chart.Axes(xlCategory) _
.MaximumScale = Target.Value

Can anyone help me?