To do what you describe, you'd pretty much be making an entirely new game from scratch. None of the assets could be reused and the old engine would be no use (even if you had the sourcecode, it's a buggy, ancient mess).
Writing a new engine that does exactly the same stuff, but better? That
can be done, could be far less buggy than the original, and may yield limited graphical improvements (it'd still be 90s graphics, but with some modern tricks thrown in). In fact, if you look up XL Engine/DaggerXl, you'll find someone's been chipping away at exactly that.