this question is similar to many other questions in life. such as, someone with no experience of driving a car, wants to be a F1 race driver. the answer to your question my friend is: you start with a nice spreadsheet called Excel with its VBA. I saw couple of Matlabs and even R in this thread. I just laughed. I also saw someone say "c++ in 21 day". I laughed again. louder. the complexity in quantiative modelling in C++ is beyond every other language named on this whole site. it is the final item you might want to look at - provided you've mastered something lower - and only when there is no other choice.