If using voyager go to the Mime section in the options and "Add new."
Select what type you want it to be and fill in the extensions like those
already done. (There will be some done by the package.) Select "execute
program" frm the action section and type in the appropriate program for
what you want to load, into the text box below. %f is the symbol used to
specify that that is the place where the filename should go.