How to do request/response from the serial port communication

I have connected my laptop to the HW which is communicating through RS232 and i want to extract possible request/response from the port. For example:

If i send

Request: 3B 16 07 xx xx xx

i would expect the response which will read approx 50bytes of data in format

Response: 3B 16 01 02 03 04 05 .................................................... till 50 bytes

Any information on how to do this would de really helpful.

Thanks