You might not like the answer.
What you want to do is pretty simple in the Saitek SST programming software.
Watch this video and FroogleSim will show you exactly how to do it.
https://www.youtube.com/watch?v=Hr9Oi1jc4wgThe X55 programming software is a rehash of the programming software for the X52.
The video covers 'edge cases' that will show you how to program a button (esc in AH) to bring up the clipboard. Then how to create 'bands' on the rotary (wheel) that will allow you to zoom in and out ([ and ]). What is presented will work with any rotary. I have mine programmed just like you described.
Now that I've done this a few times, I find it's pretty easy and useful.
Good luck.