Dim ClientHandles(0) As Long
 
     Dim ServerHandles() As Long
 
     Dim Values(0) As Object
 
     Dim Errors() As Long
 
     Dim ItemIDs(0) As String

      ClientHandles(0) = 1
      ItemIDs(0) = TextBox1.Text

MyOPCItemColl.AddItems(1, ItemIDs, ClientHandles, ServerHandles, Errors)