Currently, the numpad does the usual things(input numbers and so on). numlock does nothing.
I wonder if you can differentiate numbers/char entered on the numpad from those typed on the main section of the keyboard.
I am on MacOS if relevant(VimR).
There are special keys
<kPoint>, which can be mapped separately, e.g.,
inoremap <k0> Zero inoremap <k1> One ...
I checked this with GVim running on Windows 7; the behavior on macOS might be different.