You might want to scratch the "\n" for forum posting. Haha...
If you really want to do something like this, you'll need to mess with the API, which is actually not a good thing to do.
I'm pretty new to scripting and programming, in general, but I've been scripting in Mel for the past year. You can't change it using MelScript. Python brings better functionality from its end, to Maya, and is essentially emulated, for all intents and purposes, in Maya.
When coding with Python, you end up calling out MelScripts and Mayas functions (or the ones it allows you to use, when using Python). It doesn't actually let you mess with the mouse buttons.
If you want to mess with the API, which is the actual code that Maya utilizes for running, then you need to know C++. Mel runs off of C++, but C++ functionality and usage is not brought directly into Maya. From what I've learned, it's so the user doesn't actually screw up the program or have full access to Mayas internals.
TL;DR
No, not really. There might be a way, but I haven't found anything in relation to it.
Why would you though? You'd end up not being able to deselect, reselect or select a new object, unless you were intending to do everything through melscript. AKA:
select object,
move it with new mouse buttons,
click inside mel-coding box,
type "select -clear"
enter
select next object
repeat inefficient workflow