from GetTagName method, I can retrieve server name and PItag as a string,
for example "\\Servername\PITag"
I realise I can use the following method to get descriptor
Dim server As PISDK.Server
Dim piPtDescriptor As String
piPtDescriptor = Server.PointAttributes("descriptor").Value"
I don't know how to use the return string from GetTagName method to pass it to server object.