Programming a custom Expert Advisor (EA) for MetaTrader 5 (MT5)

Hello

I want to make a strategy. The description is uploaded in a file. It uses MA 21, MA 50, Williams indicator, and RR 1:1, it uses overbought and oversold conditions

Strategy is composed of MA CROSS (21,50) and Williams %R 

Time frame is 4h

When 21 MA is above 50 MA, bot looks for buy opportunities. When 21 is below 50 MA, bot looks for shorts opportunities

To enter a long position, for example Long: line on Williams %R has to go below -90, then come back to range and close above -80. The 4h candle must close for entry to be valid (so candle closure must happen). SL is 30 peps below previous 4h candle (not the one that closed above -80, but previous one). TP is the same as SL. So RR is 1:1. There is a runner left, so when price reaches TP, 80% of position is closed and SL is put on BE, thus leaving 20% of position as a runner

To enter a short position: MA 21 must be below 50, Williams must be overbought cross -10, and then 4 h candle must close below -20 the sell position is entered. SL is 30 peps above previous 4 h candle. TP is the same as SL, RR=1. 20% of position is leaved open when price reaches TP, and SL is put on BE

Kind regards