Is it possible to do that?
No. Any such functionality would have to be coded in the script directly and even then it's severely limited by what AE will actually allow.
There is something out there called ft-Toolbar from aescripts + aeplugins that (I think) lets you set keyboard shortcuts for scripts. It does a lot of other useful things too, so you might want it anyway, but I'm pretty sure it lets you set keyboard shortcuts for thing you put on the toolbar.