How to manage a triple pointer in C++

I tried to solve a problem with triple pointer using dynamic memory but I had a problem. I tried to create a triple pointer with 2 static dimensions to try to count the exact number of character strings that I would need. The reason of using that static pointer is to assign the correct number of subjects to the students that I will show soon. In this problem I had 2 txt docs. First I had a number of students and their IDs

Then I had a number of registers with many subjects that I need to add to the students according their IDs or codes I tried to create a static double pointer to save and add the subjects to the students but I didnt know how to manage the double static pointer

Another functions in C++