Is it possible to read "on line" all the events with an external application written in VB.NET or Labview or C++ ... ?

Yes it is possible to access the spectra data during an acquisition with an external application in VB (also the actual .Net version VB2008) or LabVIEW or C++ or Delphi or other program languages. It is shown in the example applications supplied with the DLL software interface. It is also possible to do some calculations with the event data using a self-written DLL, for example to define calculated parameters. Some programming is necessary to write a DLL or modify the dmpa3.dll with a custom function. It is also documented in the MPA-3 DLL software interface.