Hi
I have a trading system that is set as:
1) Find a stock that has the RSI below 25 (daily) and buy the stock.
2) Find the maximum of the last two candles to place the selling point.
3) This selling point moves every day to the maximo of the last two days until it sells.
4) In case  of no sell, the trade transaction is terminated on the seventh day.

How would I do this programming?

Other than #4 you can achieve the rest. In another post of yours I have mentioned that this request has arrived few times. I will probably make an improvement to cater for this.