As State Treasurer Kate Marshall and her staff move as quickly as they can to flesh out an initiative that will invest state funds in private companies in the state, private investment figures say the plan may attract significant chunks of private capital into Nevada as well.A proposal approved by the Legislature this year allows Marshall's office to invest up to $50 million from the state's Permanent School Fund into private-equity investments everything from venture capital for startups in Nevada to buyouts of existing businesses.Economic development officials have said the plan provides a significant stream of capital in a state …