Report Descriptors - Mouse

There are 6 buttons(remote on/off, page up/down,scroll up/down) in the wireless presentation mouse. I have to create the report descriptors for this wireless presentation mouse.
The following is the report descriptor for a standard 3-button mouse.
Usage Page (Generic Desktop),
Usage (Mouse),
Collection (Application),
Usage (Pointer),
Collection (Physical),
Report Count (3),
Report Size (1),
Usage Page (Buttons),
Usage Minimum (1),
Usage Maximum (3),
Logical Minimum (0),
Logical Maximum (1),
Input (Data, Variable, Absolute),
Report Count (1),
Report Size (5),
Input (Constant),
Report Size (8),
Report Count (2),
Usage Page (Generic Desktop),
Usage (X),
Usage (Y),
Logical Minimum (-127),
Logical Maximum (127),
Input (Data, Variable, Relative),
End Collection,
End Collection

Like that, How can I define report descriptor for my presentation mouse(6 buttons-on/off, page up/down, scroll up/down). I will change the number of buttons. Is it necceary to add additional lines?. What are the lines I need to add?.