[flexcoders] e4x Filtering with a variable?

[flexcoder2008]

I have an XML structure that gets built dynamically.  Nodes are constructed 
with a number appending the node name and the number of these nodes depends on 
values in a database.  The structure looks like this:

<RootNode>
    <Item1 />
    <Item2 />
    <Item3 />
    
etc...


Now I want to access a particular node using a variable.

For example:

var i:int = 2;
myXML.RootNode.Item{i}

but this is not working.  How can I create an E4x expression that appends a 
variable value onto a node name in the filter expression?