What does that macro actually do.
I can tell you, but even if you can't write text-based programming yet, if you want to learn about it you need to learn by reading it.
First, you must identify an area of memory to hold a value, and what type the value is. The typing is very confusing at first, but tells the program how to handle the information. In the Easybuilder macro case, the int type is a 16 digit binary integer value. The identifiers are the names that will be associated with the value contained in that memory address. This is called "declaring a variable."
Then, I get the value held in a PLC memory location and store it into the memory space of the variable I declared using a function built into the EasyBuilder software. After that, use an assignment statement to add one to the value, but store it in the same place. Then I write that value to a memory location within the HMI so that I can use that value for comparison to set my limits.
I strongly suggest you start learning SOME text-based language. From what I hear python is pretty popular. I've generally used C, but it is a VERY difficult language to learn, so I strongly suggest python. It is pretty popular around school and just about every class in every branch of our of STEM departments use it, including econ and finance classes. Even my diff EQ class suggests we use python for some applications when we are doing numeric evaluation.