Arduino Bluetooth + GPS Bluetooh Mouse

I have an Arduino Bluetooth and a hama Bluetooth GPS mouse.
I already established a connection between the Bluetooth GPS mouse and my mobile phone so that I can read the gps strings. Instead of this I now want to receive these strings directly on the Arduino.

When I simply do serial read like this:

void loop(){
    digitalWrite(ledPin,HIGH); 

    if( Serial.available() >= 5 ) {  // command length is 6 bytes
      cmd0 = Serial.read();
      cmd1 = Serial.read();
      arg0 = Serial.read();
      arg1 = Serial.read();
      arg2 = Serial.read();
     }
    
    char message[5] = {cmd0,cmd1,arg0,arg1,arg2};
    char newMessage[5];
    Serial.print("["); 
    
    for(int k=0;k<5;k++){
      Serial.print(message[k]);
    }
    Serial.print("]");
    delay(100);  
  
}

The serial monitor prints [SYNTAX ERR]. I think it has something to do with the baudrates but I don’t know what to try. Can somebody help me out?
Thanks.

What is supposed to be sending serial data to the Arduino? The GPS mouse?

If it's the mouse, what tells the mouse to start sending data? Why would it be sending data in 5 byte chunks? Why does the comment say that the command length is 6 bytes?

Where are cmd0, cmd1, arg0, arg1, and srg2 declared? Why are you storing data in 5 separate variables, and then storing into an array? Why not just store the data in the array in the first place?

Where is the rest of the code?

I'm sorry, it is instead a bit confusing. Should have posted a better code. The command is inrelevant (6 bits blabla).

The GPS mouse continously sends data. By the serial read I hope to receive at least something. If this works I can go further but at least this should give results first I guess.

The bluetooth GPS mouse works on 4800 baudrate where the Arduino BT communicates with the PC on 115200.

You seem to be outputting data on the same serial port that the data came in on. Is the GPS mouse capable of displaying data?

I suspect that you really need to be using a software serial port (NewSoftSerial) for reading the GPS data, and writing it out over the hardware serial port.

If that is the case, to verify that the mouse IS transmitting:

NewSortSerial gpsMouse(rxPin, txPin);

void loop()
{
   while(gpsMouse.available() > 0)
   {
      Serial.print(gpsMouse.read());
   }
}