Yip, with a small tweak, like this (un-tested) assuming it would be OK to change every instance found ...
Code:
For Each $Filename In $Array
?"Found = " + $Filename
$XML = LoadXML($Filename)
WriteXMLValue($XML, "config/Lib/Chat/HistoryDays", 123)
SaveXML($XML, $Filename)
Next
