You'll need a switching device such as a logic-level MOSFET - but first you need to establish how much
current the drill motor draws under full load - the switching device has to be able to handle
this much current without overloading or overheating.
You also should realise the trigger switch for a drill is a safety device first-and-foremost,
that cuts power to the motor if the user lets go - defeating this mechanism means you have
to think about safety issues yourself.