Edit a few lines in XML file - use values from popup?

I'm trying to create a script that can be used for editing an XML file. I want the script to show a popup and ask for which text to insert.

Example:

"Insert the server address and press OK."

And when the server address has been typed in it should insert that and then go to the next line and show a new popup.

These are the three lines I want to edit. Server, to and from.

<Actions Context="Author">
<SendEmail>
	 <Server></Server>
	 <To></To>
	 <From></From>
	 <HeaderFields />
</SendEmail>
</Actions>

Can it be done easily?