I guess, that you mean: https://www.mathworks.com/matlabcentral/fileexchange/28603-inputemu-keyboard-mouse-emulator-v1-0-1
Perhaps this is sufficient already:;
robot = java.awt.Robot;
robot.keyPress(java.awt.event.KeyEvent.VK_ENTER);
robot.keyRelease(java.awt.event.KeyEvent.VK_ENTER);
