Simple answer is no
You can buy a regulator cheaply at machine mart or other welding suppliers and would be safer than making an adaptor. You may need to invert the fire extinguisher due to some of them being a dip tube type. i.e the outlet is below the liguid level in the bottle. This causes freezing of the regulator and stops the flow of gas. I use old extinguishers for most of my welding. not the best gas to use but works out cheaper.
Chris