You can do this several ways. The NI-DAQ help for AI Config gives a good explanation of the various ways you can add mutilple channels. The easiest way is in the channels array specify you want to use channels 0:3 (which is channels 0 through 3). If you don't have consecutive channels then you can use commas (0, 2, 4, 6). There are other ways to do this, but these are the 2 easiest.