Thanks RayB, I just found it on the FAQ at ultimarc, I was asking because It didnt say anything on the main page of the optipac where its telling you all about it, just found it though, sorry. "What about mouse buttons?
Four inputs are provided for mouse buttons, two for each port. These inputs can be wired up together with I-PAC button inputs so that control panel buttons can perform dual function: mouse buttons and normal key-type inputs. So you could use your trackball as a mouse with two of the control panel buttons working as mouse buttons and also have these buttons work in games via the I-PAC. "