Using VSTO to access the CustomXML of the word document file

Here is the code for accessing the CustomXML file of the word document file

foreach (System.IO.Packaging.PackageRelationship relationship in myPackage.GetRelationshipsByType("http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"))
            {
                Uri documentUri = PackUriHelper.ResolvePartUri(new Uri("/", UriKind.Relative), relationship.TargetUri);
                documentPart = myPackage.GetPart(documentUri);
              
                foreach (PackageRelationship objPckRel in documentPart.GetRelationshipsByType("http://schemas.openxmlformats.org/officeDocument/2006/relationships/customXml"))
                {
                    partUri = PackUriHelper.ResolvePartUri(objPckRel.SourceUri ,objPckRel.TargetUri);
                    objPackPart = myPackage.GetPart(partUri);
                    doc = new XmlDocument();
                    doc.Load(objPackPart.GetStream());
                    try
                    {
                       objNode = doc.SelectSingleNode("/root[1]/ProjectData[1]");
                      string strXML = objNode.OuterXml;
                      break;

                    }
                    catch (Exception ex)
                    {
                        //do nothing
                    }
                }
            }