star "*" hotkey setup

in Mach3 I'm jogging my cnc router with a usb numeric keyboard pad (the one with just numbers) and it works great, jogging x, y and z and homing but I need to have a "zero all axis" hotkey setup as well, can someone help me with the procedure to configure my "*" or "5" or "/" or "0" key to zero all axis (or at least the z axis)

I think the available keys on that numeric keypad are "*" "/" "0" and enter
all the other ones do something already as follows:

num lock turns the numeric pad on or off
"-" decreases the spindle speed
"+" increases the spindle speed
"del" or "." deletes one block of g code
"7" sends all axist to home
"8" jogs y+
"9" jogs z+
"4" jogs x-
"5" does nothing
"6" jogs x+
"1" turns a m1 stop on on run screen
"2" jogs y-
"3" jogs z-

Thanks