processing XML using powershell

# load XML document from file
$xmlfile = "C:\Users\user1\Documents\123.xml"
[xml]$doc = Get-Content $xmlfile

# find element by tag name
$te = $doc.DocumentElement.SelectSingleNode("token")

# check if element exists
if (-not $te) {
    # create the element if not exist
    $te = $doc.CreateElement("token")
    # append to DocumentELement
    $doc.DocumentElement.AppendChild($te) 
}

# set element value
$te.InnerText = "XXXXXXXX"

# save the document back to the file
$doc.Save($xmlfile)

see also

• DotNet API DOC about XML