USB GPIO JAVA DIGITAL COMMANDS

I have just recieved my USB GPIO 64 channels. installed the driver, connected to java by this code:

SerialPort port = new SerialPort("COM6");
try {
/*Try to open port*/
if(port.openPort() == true){
System.out.println("Port opened successfully...");
}
else{
System.exit(0);

}

this works OK. but now I need to send a digital signal to a specific pin out of 64 pins, like HIGH or LOW , PULLUP or PULLDOWN.
How to write that in Java Netbeans ?