Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml
Imports System.Xml
Imports System.IO
 
Module Module1
    Sub test()
        Dim fileName As String = "template.docx"
        Dim customXMLTemplate As String = "<root> <SdkName>!Name!</SdkName>" & _
          "<Version>!Version!</Version> </root>"
        Using wordDoc As WordprocessingDocument = WordprocessingDocument.Open( _
        fileName, True)
            Dim mainPart As MainDocumentPart = wordDoc.MainDocumentPart
            mainPart.DeleteParts(Of CustomXmlPart)(mainPart.CustomXmlParts)
            Dim customXmlPart As CustomXmlPart = mainPart.AddNewPart([u]Of _
              CustomXmlPart)()
            Dim customXML As String = customXMLTemplate
            Dim regexName As New Regex("!Name!")
            Dim regexVersion As New Regex("!Version!")
            customXML = regexName.Replace(customXML, "Open XML SDK")
            customXML = regexVersion.Replace(customXML, "1.0")
            Using ts As New StreamWriter(customXmlPart.GetStream())
                ts.Write(customXML)
            End Using
        End Using
    End Sub
End Module