Is it possible to get an mt4 indicator converted to mt5 is I don't have the source file?

 
I would like to get an indicator converted to mt5 from mt4, but I only have the ex4 file and not the source code. Is it still possible to get it converted from the ex4 file or what I need to have it built from scratch?
 
  1. No source, can't be converted.
  2. Reverse engineering is basically guessing on how it works. How good is your guess?
 
You could try to find the creator and ask for a conversion. If it's a public release you may find the source code in some forum (or here in the code base).