You should try these tutorials first:
https://fxdreema.com/forum/topic/4208/tutorial-06-my-indicators-in-fxdreema
https://fxdreema.com/forum/topic/9105/tutorial-working-with-ex4-ex5-indicator-file
However, there is no guarantee that it will work on fxDreema. Especially when considering MT5 indicators.