He went to school with Karen, and vowed revenge when she beat him for student body president with the aid of breast implants.
He attempts to buy out Walker Inc. (under the pseudonym Frank Woolley) but is thwarted when Karen blackmails the board of directors into unanimously re-electing her as CEO. 
Scott creates a fake dating profile to meet Karen, pretending to be a morbidly obese man (with the screen name "ElevatorHazard") in order to lure her in. Although he stands up to Beverley Leslie for her, and makes nice with Karen, she ultimately does not feel the same way. 
Man. That is one sweet office that Stanley Walker had. Although I might replace the omelet station with a-- oh, I don't know-- a computer. — Board Games