Key command to toggle vertical mouse scrolling to horizontal?

Hi!

I'll start by saying that I was a huge fan of two features from the now defunct MouseWorks for PPC:

- the ability to create an assignable, custom pop-up menu, full of custom key commands, for every Mac application.

- the ability to turn the mouse middle/scroll wheel button into a toggle function that, when pressed, makes the scroll wheel scroll horizontally (and back to vertical scrolling when clicked again).

It blows my mind that I can't find another mouse utility/app that allows this kind of customization. I am playing with SteerMouse right now, but there doesn't seem to be a way to assign a scroll wheel horizontal/vertical toggle to the middle(any) button. I am able to imput a custom key command, but I don't know of an Apple OS function that toggles scrolling like this (not including holding the shift key, because I don't see how this would work) that I could assign a key command to and therefore associate with a mouse button.

Can anyone think of a logical work around for this? Holding down Shift is not intuitive enough. Also, the 'Click-hold' option in SteerMouse allows me to check off Shift as a modifier also to be held, but that's no good because there is no way to only have a modifier key held without the click (the click being held causes chunks of text the cursor might have been around to be dragged).

As popular as MouseWorks was, I can't believe no one has attempted to rip off its best features to make a well-deserved buck!

Thanks for your time and critical thinking!