#!/usr/bin/perl
    use utf8;
    my $file='myimageऄwithधDevanagariमcharsफ.png';
    my $filenew=$file=~ s/(.)(?{ if (ord $1 >127 ){'x'} else {$1} })/$^R/gr;
     
    print "before: ",$file,"\n";
    print "after: ",$filenew,"\n";