I would like to know definitively, whether or not, Maltodextrin from corn and High Fructose Corn Syrup are essentially the same?

Not. Both may be made from corn (MD is also made from wheat), but HFCS is first and foremost a sweetener whereas MD is often used for its texture or thickening rather than sweetening properties. HFCS is a physical mixture of fructose and glucose whereas MD is a polysaccharide of glucose - usually 3-17 units long. Both HFCS and MD contain a large number of calories.