I need help with mouse setting /scroll hotkey

So I was programming some hotkey settings to my 9 button mouse for browsing, like volume up/down, forward, back, close tab, duplicate tab. It's really handy.

BUT I accidentally overwrote the one for the mouse wheel button (you press the wheel down), which I use ALOT. I CAN"T FIND ANY INFO ANYWHERE ON HOW TO GET IT BAAAAAAACK!

The function/hotkey I'm looking for: When pressed, the pointer turns into a 2 or 4 direction arrow, and you scroll the page in whichever direction you move the mouse. I even tried uninstalling/reinstalling the mouse, but it remembers the latest settings. Anyone help?

I spend a half hour over complicating it hahaha. FINALLY I happened to switch the setting back to 'middle button' and the scroll 'function' I couldn't find referenced is back. Wth lol.

Now along with volume control, it does forward back and duplicate tabs, as well as auto scroll and close tab. I want more buttons now. Like to go to specific webpages you always go to would be cool.

Thanks for teaching me a new trick.