In light of your recent question, design the open function, it sounds to me like you're trying to search through a bunch of Perl scripts to change the way your open commands are written, without having to perform those edits by hand. In other words, I think this question is related somehow to the question you asked a day ago. If that's the case, you're still approaching the problem the wrong way. Rather than trying to do an s/// operation on each open command within all of your scripts, you could just insert the use open ':locale'; pragma at the top of each of those scripts, as I pointed out in Re^3: design the open function.

If I'm misunderstanding the question, or simply reading too much into your recent questions, I apologize, and implore you to give us a hint at the bigger picture; what it is you really want to do, so that we might help you find a real solution rather than a kludge.