SPRINGFIELD — Top executives of utility giant Commonwealth Edison faced tough questions from state regulators Wednesday as they publicly apologized for the lobbying scandal that is forcing the company to pay a $200 million criminal fine.“That’s the first words I wanted you to hear out of my mouth,” ComEd CEO Joseph Dominguez told members of the Illinois Commerce Commission. “But the last words I want to leave you with is that I’ve observed the character of this company. I know what our job is and leading it and I know the …