Infinite menu with scroll buttons

Hello,
I’ve had a look over the numerous infinite menu threads but I can’t seem to find what I’m after. I need to adapt the menu so that it will work with a left and right scroll button rather than the mouse position. I have got this working but the problem is the menu does not move with easing or inertia. This is what I need to do.

If anyone has any ideas or could point me in the right direction it would be much appreciated.

Cheers