C++ Read CSV file and do calculation

[rainmeiwah]

Pls help... I'd need to read in a csv file (pls see below example) and need to calculate the sum/average of column 3 and 4 based on some condition e.g. for Jun data, and then output it.

2010-06-13 10:00:00,123,333,44.5,50
2010-06-13 10:10:00,124,324,43.7,49
2010-06-13 10:20:00,122,321,45.9,48
2010-06-13 10:30:00,100,342,40.9,50

1) I do not know the number of rows of input file, how to design to read in all rows?
2) how to read in "comma" separated data?
3) how to get in date, column 3 and 4 data only?
3) after read in, will need to store it for further calculation? how to do it? use vector?

can i have some example please? thanks!
the worst is i cannot use STL vector, have to create my own...