Hi Alain,
here's the partial answer, see the Internet Explorer way.The issue is that you'll get the printer dialog box in which you'll have to press the button to print manually.
If you're able to somehow find the way to do it automatically, it'd be preety cool. There are few topics on web that are concerned with this dialog box, but in other environments, so if you're brave enough, try them in MATLAB.
Sending keystrokes to the opened application, also useful but due to the fact that printing occurs in another window, sending enter won't close the dialog box. See here.
Edit so the answer is on top:
WordPadProcess = System.Diagnostics.Process;
WordPadProcess.StartInfo.Arguments = "/p filename.txt"
WordPadProcess.StartInfo.FileName = "C:\Program Files (x86)\Windows NT\Accessories\wordpad.exe";
WordPadProcess.StartInfo.UseShellExecute = 0; % you get the error below if run with true
WordPadProcess.Start();
while ~WordPadProcess.HasExited; pause(0.5); end % MATLAB won't proceed further until WordPad is closed
%Message: The Process object must have the UseShellExecute property set
%to false in order to use environment variables.
If one wants to close the process, it can be done with
WordPadProcess.Kill;
