However I don't think that supports a wheel by default! To get that you'll have to make your own HID report descriptor by mashing the wheel's descriptor into the tablet bit...
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Thanks for posting up how to send the scrollup/down - that's great.
You're asking how to send Absolute Position? Much like a tablet/touchscreen?
I think what you need is USBTablet: http://www.espruino.com/USB#tablet
However I don't think that supports a wheel by default! To get that you'll have to make your own HID report descriptor by mashing the wheel's descriptor into the tablet bit...
https://github.com/espruino/EspruinoDocs/blob/master/modules/USBMouse.js#L38
https://github.com/espruino/EspruinoDocs/blob/master/modules/USBTablet.js#L40
But at that point my knowledge is at an end - you'll have to consult Google and use some trial and error to figure out what will work.