harderic:
Ok, i thought using the "SD.open" loads the entire CSV into memory, but if not then I just need to overwrite the old stored values each time i read the code.
Think about it, the Uno has 2K of RAM and SDcards can be 32GB... 7 orders of magnitude difference
But how do I read in the columns and store them as 'long' variable type? and then the next time i read from the CSV make sure I've incremented to the next row?
By parsing on the fly. Parsing is reading a string of characters and breaking it up into the structure you want,
and here you probably need simple ad-hoc parsing using a small state-machine. Without programming
experience you will be on a learning curve, but a worthwhile one(!)