Logitech Mouse how to get the up and down button to be Numpad 1 and 2

[magoo1magoo]

what software do i need or is there something i need to do on mac, im new to the mc. Im just trying to get the left two keys on my mouse to substitute for my lack of a numpad. and maybe get the middle button as well to be numpad#3

 

[J the Ninja]

Steermouse can map any mouse button to any keyboard shortcut you like. Including application specific shortcuts. And app-specific tracking and scrolling settings.