What do you do after you've won the gold rush? When you've claimed the richest veins of ore? That's the big question for Epic Systems, the medical software giant that has become Dane County's signature company with 8,000 or so employees at its fairyland campus in Verona. Epic is the big winner in the federally subsidized effort to shift American medical care from paper to electronic records. As part of President Obama's economic stimulus plan, Congress approved a $27 billion incentive program in 2009 that touched off a mad scramble to modernize health systems in the name of improved efficiency and better care.