http://msdn.microsoft.com/en-us/library/bb242669.aspx
consider this link, which gives the Object Model Changes Since Microsoft
Office 2003 of Excel object model

can u please give complete idea regarding the status "Hidden". Why I want to
know about it.

some of the properties which I am using are Hidden in 2007 object model. But
they still exhibiting the same functionality.

For example:
Chart Object.PlotArea.Fill returns ChartFillFormat object. But in 2007 both
the ChartFillFormat object and property Fill of PlotArea are hidden.

Actual requirement is like following.
..PlotArea.Fill.Visible = True
..PlotArea.Fill.OneColorGradient Style:=msoGradientHorizontal, Variant:=1,
Degree:=0.3

So kindly help me in this regard.

Thanks in advance.