Check out the
Custom Stats Guide for an overview, and the
Tutorial: Custom Reports and Statistics goes into much more detail.
The simplest way to add "limped pot" is to include "char_length(cash_hand_summary.str_aggressors_p)=1" in your column expressions. The length of that string is how many aggressive actions there were preflop (the BB counts as an aggressive action for this purpose) - see
this thread for more information on that.
You can use ">1" for raised pots (or "=2") if you mean single raised pots specifically) and "=3" for 3bet pots.
If you're having problems please tell us where you're stuck so that we can advise you.