#!/usr/bin/perl -w

$string = "Test: FileNames can't have / \\ and other special characters";

%s = (":" => "COLON", "/" => "FSLASH", "\\" => "BSLASH");
$t = (join "|", map quotemeta($_), (keys %s));
$string =~ s/($t)/$s{$1}/g;

print "$string\n";