[As mentioned. this question isn't in any way RC.SE related, as it's about generic devices and modern computers. I'll vote for moving to EE.SE and answer as if's already moved]
Is there any way that I could detect from the laptop this pedal being actioned? Is there any way extra hardware that would make this possible?
Extra hardware will do the trick - always.
Adapting it to audio input will require active electronics (an amplifier), thus you'd need a second board and a power supply.
Now, if your Laptop still holds a real Joystick port, then it might be possible by simply building a connector, as the signal might be most likely a resistive (*1), much like from an analogue (PC) Joystick. Then again, having such a port seams unlikely :)
The next best way may be to hack a USB-Joystick as interface. Remove all 'joy' ... aeh mechanical parts and hook a connector for the paddle to the input - maybe with sole analogue adaption if it uses a different ranged resistor.
The ultimate best way is to build your own controller. Like using an Arduino. Hardware would be simply adding a resistor and a connector to the analogue input. Power supply already comes with USB. The controller software will be rather simply presenting the digitized value to whatever data format / logical interface you'd prefer. Most simple would be as serial port, as handling them is already part of basic Arduino workings, Or present it again as joystick interface, more appropriate anyway for analogue data. There are plenty examples on Arduino Sites.
*1 - As DirkT already mentioned.