Bind to a particular row and column of a dynamic grid?

I'm new to WPF, so perhaps I'm going about this the wrong way. I'm
trying to create a grid that contains a collection of objects. The
number of rows and columns of this grid is dynamic; ideally those
properties would be bound to a couple of properties of a custom object.
The position of the objects within the grid would ideally be bound to
properties of those objects themselves.

A Grid allows items to be bound to particular rows/columns, but the
total number of rows/columns must be static (at least, from a pure XAML
perspective). The UniversalGrid allows binding to the total number of
rows/columns, but items cannot be bound to particular rows/columns (they
simply flow horizontally, wrapping with the number of columns).

Below is the closest I can get to what I want. Am I on the right track?
Can anyone point me in a new direction? I'm beginning to suspect it
may require some codebehind.

Thanks in advance,

-Phil


<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >

<Page.Resources>

<XmlDataProvider x:Key="InventoryData" XPath="Inventory">

<x:XData>

<Inventory xmlns="">

<Wafer rows="3" columns="3">

<Die row="0" column="0" value="One"/>

<Die row="1" column="1" value="Two"/>

<Die row="2" column="2" value="Three"/>

</Wafer>

</Inventory>

</x:XData>

</XmlDataProvider>



</Page.Resources>

<ItemsControl>

<ItemsControl.ItemsSource>

<Binding Source="{StaticResource InventoryData}"
XPath="Wafer/Die"/>

</ItemsControl.ItemsSource>

<ItemsControl.ItemsPanel>

<ItemsPanelTemplate>

<UniformGrid IsItemsHost="True">

<UniformGrid.Rows>

<Binding Source="{StaticResource InventoryData}" XPath="Wafer/@rows"/>

</UniformGrid.Rows>

<UniformGrid.Columns>

<Binding Source="{StaticResource InventoryData}"
XPath="Wafer/@columns"/>

</UniformGrid.Columns>

</UniformGrid>

</ItemsPanelTemplate>

</ItemsControl.ItemsPanel>

<ItemsControl.ItemTemplate>

<DataTemplate>

<Button Grid.Row="{Binding XPath=@row}" Grid.Column="{Binding
XPath=@column}" Content="{Binding XPath=@value}"/>

</DataTemplate>

</ItemsControl.ItemTemplate>

</ItemsControl>

</Page>