Hi RWorker,
Can you try below this code in onAfterChange event of that field.
var nodeValue = XDocument.DOM.selectSingleNode(“XPath of your fieldâ€).text;
if(nodeValue >100 && nodeValue < 1000)
{
var focusFieldNode = XDocument.DOM.selectSingleNode(“XPath of where do you
want to set the nodeâ€).text;
XDocument.View.SelectText(focusFieldNode, 1);
}
Hope this helps you.