Yes there are such things available (unfortunately I'm short of time to search just now) but you will need something capable of providing a few hundred watts with a roughly sine wave 50/60Hz, 240 volt output. It's not likely to be cheap!
You will need an inverter with a transformer. The inverter to give you alternating current at 50Hz (UK supply, 60Hz USA) from your car`s DC supply and the transformer to raise the voltage from 12vdc to about 230vac.
There are both solid state units and motorized. Beware those that provide a square output; they may be fine for irons and kettles but not PCs.
I suspect you're looking at the wrong sort of things. Since laptops usuially run on DC from aa external transformer/power supply - I can't quite see the point of making DC into 230V AC then transforming it back down to DC to run the laptop.
Can you give us the specification of your regular laptop supply please (it'll be on the lable).
I bought a transformer from my local computer shop for £35 which plugs into the accessory socket in the car with different power outputs and plug connections, my laptop is an HP Athlon64 3200+ which needs 19volts and 120w it is a Vanson Model: SDR-120W