Vista - ListView column backgrounds

All -
I want to have a different background for a specific column in ListView.
For instance a sorted column's background / a third column's background etc)

I tried to specify a CellTemplate on the GridViewColumn node, but i have
run into problems:
Ex:
<GridViewColumn Header="MySpecialColumn" >
<GridViewColumn.CellTemplate>
<DataTemplate>
<Grid Background="Orange" HorizontalAlignment="Stretch">
<TextBlock Padding="2" Text="{Binding XPath=@Subject}"/>
</Grid>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>

Q1:
I am not specifying the width of the GridViewColumn explicitly (so the
column will size to fit the content).
Hence the cell background for each row fits the content background only.
For instance the 1st row of my target column has text as "hi" and the second
row has "World" - the background "Orange" is getting applied only for the
length of the text (hence its short for hi and a bit long for "World".)
This is inspite of setting HorizontalAlignment to stretch for the Grid.

How to make the grid width span the entire GridViewColumn width?

Q2:
I tried to set a dynamic binding of the width of the Grid to the width of
the GridViewColumn. How to specify the binding here?

I am not able to use RelativeSource - FindAncestor - since GridViewColumn is
not on the visual tree of the grid. TemplatedParent gives me the ListView
which i dont want.

So - from the UIElement "Grid" inside the DataTemplate node - how to
reference a property of "GridViewColumn" like Width for binding?

Please note that the binding worked with specifying ElementName and
explicitly specifying a name for the GridViewColumn - but i dont want to do
this.

Thanks in advance.

Regardz
Grafix.