Needed to read right & middle mouse buttons for a project, so I finally got around to digging into the hi object - and realized that by holding down various combinations of the 3 buttons, I could send mouse coordinates to 7 different locations.
The patch uses accum objects to gather up momentary xy mouse movement, and the int objects under the pictsliders are there so that coordinates of each mouse click begin at previous location.
Tested with a Macally 3-button mouse. Works fine. Unfortunately Apple USB mouse only reads one button at a time, so the combos don't work. Not sure which mouse behavior is more common.