MOUSE! MOUSE! MOUSE! SPECIAL SUPER MOUSE FOR EXCEL!
Grinler is right of course.
But there is a solution. A $10-15 solution.
Actually sky is the limit.
I have a mouse with a wheel on top (Kensington). In Excel to go one way, I click the wheel to go horizontally, then I scroll left or right. To change scroll direction, I click the wheel again and it scrolls up and down now.
When the wheel is clicked you get a little icon showing the direction for your next scroll. It's fabulous. And it confirms the mouse works.
Few applications don't honor this mouse (VBA behind Excel is one of them), but most do. Bleeping Computer almost does, except there is no horizontal scroll bar, but I see the mouse willing to change direction.
Now where is Jason's CAT?