If you do a search for "EMPOWER" in this forum you will find what you need.
Otherwise a good start is either
www.targus.com or
www.apc.com as they both make power converters for the Dell you have.
There are 2 options: Empower (the name of the power adapter in the seat) that provides "DC" power to your notebook replacing the existing power supply and Empower to AC meaning it converts the low power seat outlet into 110V.