open FH, "<:encoding(UTF-16)", "$file_folder\\$ori_datafile" or die "can't open file";

...

#open (NEWFILE, ">$file_folder\\$new_datafile") or die "can't open file";
open (NEWFILE, ">:encoding(UTF-16)","$file_folder\\$new_datafile") or die "can't open file";
open (FIXLOG, ">$log_folder\\$fix_log") or die "can't open file";
open (ERRLOG, ">$log_folder\\$error_log") or die "can't open file";
open (FIXRPT, ">$log_folder\\$rptfile") or die "can't open file";