Access -> Excel.Application -> Chart -> Draw lines and color area

From a Access form, I
1. put some Access data in Excel.Application.ActiveSheet,
2. Displayed a line chart

In Excell.Application object, I
1. chart = app.Charts.Add
2. A line chart displayed

I want to know
1. How to drawline in the chart object
2. How to change the background color of
a rectangle area.
Thanks.
Huaqing