XML : Use of XML in Powershell scripts

I have a script with which I want users to be able to edit an XML file and have their options then utilized in the associated PowerShell script. But I don't want the users to edit the script - I want them to edit the xml file and then have those xml items set as variables in the PS script so that basically when they edit the xml file, they are editing the appropriate values in the script) -

I tried to paste the xml file and the script I created here, but it didn't format correctly...

HELP?!?! I am so lost. I find plenty of things online about using Xpath and that just doesn't seem to be correct for me....how do I go about accomplishing this, or even searching for the right way to accomplish it?

Thanks, LG