To add a source button: in the CCP software, click on the "program" tab, and the select, "Edit Buttons". From there, select your TV under the "Device" drop down menu. From there, type in "Source" in one of the unused buttons. From there, click "save" and exit out of the "Program" window. Then find the "IR Database Navigator" window on the right side of the screen. In the "IR Data From" drop down menu, select "TV" and then type in "656" in the box to the right of that.

You'll see the functions populate below. Locate the "source" function, and then "drag and drop" the function onto the "source" button you recently created on the TV device page(s).