use strict;
use warnings;
my @shell_rtn_val;

print "Enter name of file to copy: ";
my $file = <STDIN>;  # open STDIN and get input
chomp $file;  # remove the \n
$file =~s /\\/\\\\/g;  # Convert to Win32 Shell path sep
$file =~s /\//\\\\/g;  # Use Unix path's too :-)
@shell_rtn_val = `copy $file $file."bak"`;
foreach(@shell_rtn_val){
  #Let's look for interesting stuff and process it
  # $_ is implicitly searched for in each if
  # just like you wrote: $_ =~ m/regex-pattern/
 	if ( /(\d) file\(s\) copied/ ){ 
	my $num = $1;print "You copied $num files";
	}
 	if ( /cannot find/ ){ 
	print "System can't find a file by that name";
	}
	if ( /syntax/ ){ 
	print "Bad syntax";
	`copy /?`;
	}
}