Smoothed line outside data range

I want to plat a smoothed line that goes through data points without going below them. I know that this is a common problem in Excel and I know that it has to do with the spline used to calculate the curve through a data set. This however seems to be an over-interpretation of the data being used. If you were doing this by hand you would just draw a line through the points without dipping above or below the points. Is there a way to make this happen in excel? Is it possible to change how the curve is calculated?

Also, different versions seem to calculate this differently. The smoothed line graph that I make in 2004 on mac is different from the graph my advisor makes on office 2007.

Thanks.