XPath and TXmlDocument

XML example, from the OmniXML XPath demo:

<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
　　<book>
　　　　<title lang="eng">Harry Potter</title>
　　</book>
　　<book>
　　　　<title lang="eng">Learning XML</title>
　　</book>
　　<book>
　　　　<title lang="slo">Z OmniXML v lepso prihodnost</title>
　　　　<year>2006</year>
　　</book>
　　<book>
　　　　<title>Kwe sona standwa sam</title>
　　</book>
</bookstore>

Try something like this:

uses
  XMLDoc, XMLDom, XMLIntf;
　// From a post in Embarcadero's Delphi XML forum.
　function selectNode(xnRoot: IXmlNode;const nodePath: WideString): IXmlNode;
　var
  　　intfSelect : IDomNodeSelect;
　　  dnResult : IDomNode;
　　  intfDocAccess : IXmlDocumentAccess;
　　  doc: TXmlDocument;
　begin
  　　Result :=nil;
　　　if not Assigned(xnRoot)or not Supports(xnRoot.DOMNode, IDomNodeSelect, intfSelect) then
　　    Exit;
　　  dnResult := intfSelect.selectNode(nodePath);
     if Assigned(dnResult) then 
     begin
        if Supports(xnRoot.OwnerDocument, IXmlDocumentAccess, intfDocAccess) then
      　　doc := intfDocAccess.DocumentObject
　　    else
   　　   doc :=nil;
       Result := TXmlNode.Create(dnResult,nil, doc);
　　  end;
 end;

var
  IDoc: IXMLDocument;
  INode: IXMLNode;
begin
  IDoc := LoadXMLDocument('.\books.xml');
  INode := SelectNode(IDoc.DocumentElement,'/bookstore/book[2]/title');
end;

//================================================================================

procedure TForm1.Button1Click(Sender: TObject);
var
  noderef:IXMLDOMNodeRef;
  root:IXMLDOMNode;
  Node:IXMLDOMNode;

begin
  XMLDocument1.Active:=true;
  noderef:=XMLDocument1.DocumentElement.DOMNode as IXMLDOMNodeRef;
  root:=noderef.GetXMLDOMNode;
  node:=root.selectSingleNode('node1/node2/node3/node4');
  if Assigned(node) then
  begin
    ShowMessage(node.attributes.getnameditem('title').text);
  end;
end;