PeteS160:
I have looked over that several times before and they don't work in this situation. Example 5 is the only one that could possibly have been of any use but it expects the numbers and letters to come in a preset order, there is no way to alter start and end markers from the shield or to separate the values for parsing the response.
The idea behind my tutorial is to give you ideas about how to receive data. It was never intended to provide complete solutions - people's requirements are too varied. In many cases it will be necessary to make significant modifications.
What is the end-marker sent from the device you are communicating with?
Does the device send a start-marker? if so what is it?
I would start by creating the ability to display the responses from the device on the Serial Monitor. When you can do that you will have information that will help you with the task of interpreting and dealing with the responses. Develop your program in small steps.
...R