Wheel Mouse Support on Sun/Sparc?

Tor asks: "Is there a way to get mouse wheel support (button 4 & 5 events) under Solaris/Sparc? OpenWindows seems to support only 3 buttons, since that's what Sun mice have. XFree86 exists for Solaris/x86 and Linux/Sparc, but not Solaris/Sparc. Why do I need this? I have a Linux laptop next to my Sun workstation, and merge the two displays using David Chaiken's excellent x2x utility. This works great! I have patched it to allow mapping of extra buttons to keyboard events (like x2vnc), but would really like button4 and button5 events to be passed on to the applications on the Sun side."