I can't use project plan, which will obviously provide an easier fix for this

I a have a simple list of IDs and task names (pls see table below). Requirements are:

• Auto create a unique ID, which could be any number with a prefix from column C. How?
• Once a unique ID is defined it should not change against that task name. How do I detect changes if someone does change the ID cell against an existing task?
• New Unique ID to be assigned when a new line is inserted (with a prefix from column C)

• Note: New line could be inserted at the bottom or in the middle of the existing list

Happy to use power query, VBA or a semi manual way of managing this process. Any guidance much appreciated

ID Task Name
1 Task 1
2 Task 2
3 Task 3
4 Task 4