Can anyone update XML file when you change a value of each row?

Hi, If anyone can answer my question, please help me.
I'd like to know that how to get a node address for each row.
For example,
<movies>
<movie>
<title>Superman Return</title>
<year>2006</year>
<ticket>Yes</ticket>
</movie>
<movie>
<title>Cars</title>
<year>2006</year>
<ticket>No</ticket>
</movie>
</movies>
Assume that you have above XML file. When you use grid control, it will look like this
----------------------------------------------------------------------------------
title | year | ticket
----------------------------------------------------------------------------------
1 superman Return 2006 Yes
2 Cars 2006 No
------------------------------------------------------------------------------------
On this Gird window, now you want to change the title of moive "Cars".
So, you click on a editable cell and chage name of "Cars" to "Nacho Libre".
At this point, when you pass this new value to the server to update file, can you
pass the address of this node, also? (ex: //movie/title)
I also want to pass the array value of this location. For this example, Cars should be
"//movie/title[1]"(second array value).

Is there any function to get those value?
I'm working on these project by using PHP.

Thank you.