Hi John,
In the Administrator Options, under User Account & Security, The nursing level has the ability to prescribe on behalf of the provider. You can only select one provider as a DEFAULT, but the nurse will be allowed to prescribe on behalf of any provider. If they need to prescribe on behalf of another provider, they can select that providers name in the drop down box on the script transmission screen (right after you hit "Prescribe", the option is in the top right corner above the print options).