How to bind left-shift+mouse-up/down-scroll to page-up/down in Windows 7
You can do this with AutoHotkey.
Simply use this script:
+WheelUp::SendInput {Shift Up}{PgUp}{Shift Down}
+WheelDown::SendInput {Shift Up}{PgDn}{Shift Down}
The + means while shift is held.
Shift must be released before sending page up/down, otherwise it interferes (try holding shift and using the keyboard page up/down buttons). That's what {Shift Up} does.
Shift is pressed down again after sending the page up/down, so you can go more than one page without physically releasing the key.