Steps are: 1. select "<Customized projection...>" from "Select projection and datum presets" form and press "Next >" button. 2. input your datum in "Select datum" form and press "Next >" button. 3. input you projection in "Select projection" form and press "Parameters" button. 4. input your projection paramenters in "Select projection parameters" form and press "Accept" button. 5. press "OK" button.