Call SharePoint web service from excel macro vba

I have called SharePoint web service from excel macro VBA with following code from here:

Sub CallService()

    Call Add_Item("List1", "https://contoso.sharepoint.com/sites/site1/", "test item", "Title")

End Sub

.

Sub Add_Item(ListName As String, SharepointUrl As String, ValueVar As String, FieldNameVar As String)

Dim objXMLHTTP As MSXML2.XMLHTTP60

Dim strListNameOrGuid As String
Dim strBatchXml As String
Dim strSoapBody As String

Set objXMLHTTP = New MSXML2.XMLHTTP60

strListNameOrGuid = ListName


'Add New Item'
strBatchXml = "<Batch OnError='Continue'><Method ID='2' Cmd='New'><Field Name='ID'/><Field Name=" + FieldNameVar + ">" + ValueVar + "</Field></Method></Batch>"


objXMLHTTP.Open "POST", SharepointUrl + "_vti_bin/Lists.asmx", False
objXMLHTTP.setRequestHeader "Content-Type", "text/xml; charset=""UTF-8"""
objXMLHTTP.setRequestHeader "SOAPAction", "http://schemas.microsoft.com/sharepoint/soap/UpdateListItems"

 strSoapBody = "<soap:Envelope xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsd='http://www.w3.org/2001/XMLSchema' xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'><soap:Body><UpdateListItems xmlns='http://schemas.microsoft.com/sharepoint/soap/'><listName>" + strListNameOrGuid + "</listName><updates>" + strBatchXml + "</updates></UpdateListItems></soap:Body></soap:Envelope>"

objXMLHTTP.send strSoapBody

If objXMLHTTP.Status = 200 Then // 'returns objXMLHTTP.Status = 400 here
//' something code
End If

Set objXMLHTTP = Nothing

End Sub

But Above code returns objXMLHTTP.Status = 400

Can't find what is wrong. Can you ?