If I understand you correctly, you have two 220 volts hot wires and a bare ground wire. The new range that you purchased uses two 220 hot wire, whie neutral and ground. In no circumstance can you use the ground wire as the neutral, it is not allowed in the NEC code. You must have the proper circuit installed. Contact an licensed electrician. If something happens to you range which causes some damage/fire death in your house. Your household insurance will be null and void.