Often the plug of the power cord and its mate, the jack in the monitor, would have to conform with the region/country of its intended use. Having said this, then it is possible that your particular version is meant for another country but is likewise sold in your country. A picture of the monitor's connector would help narrowing the selection and possible source/supplier. Pls post if able.
Alternately, you could try viewing the different types here
or here to get the specific part number or model of the AC cord.
Incidentally, most electronics shops/stores sell a variety of power cords, perhaps a visual check would further assist you.
Hope this be of initial help/idea. Pls post back as requested, how things turned up or should you need additional information.
Good luck and kind regards. Thank you for using FixYa.