I want to build a cbot based on reverse trend buy

HI. I want to build a cbot based on this strategy

Manual entry, at every -50 pips buy X lots in percent of total balance ( account equity ) Take profit triggered at +x pips

the rebuy lots should be selectable something like at first 3x -50 pips buy 0.2% of balance then after -150pisp buy 0.5% of balance and so on. Selectable % for every rebuy