Hire a coder to "reverse engineer" the logic by watching the EA trade.
You may find Python or C++ scripts that worked for MT4 builds from 2014. These will almost certainly fail on modern files, resulting in "Unknown Version" errors.
Decompiling software you do not own violates laws. Always ensure you have the legal right to the source code before attempting to reverse engineer a file. If you'd like to move forward, tell me: Do you own the original rights to the file? Are you trying to fix a bug or just see the logic ? What build version of MT4 are you using?
Since then, MetaQuotes has significantly upgraded its encryption and obfuscation. Modern EX4 files are compiled into machine code, making them extremely difficult to reverse-engineer. Most "decompilers" you find online today—especially those claiming to be free on GitHub—are either outdated, non-functional, or malicious. Searching for "Ex4 To Mq4 Decompiler" on GitHub