$   cp Cart.pl Cart.pm 

##</code><code>##

#!/usr/bin/perl -w 
use strict;

#
# This is the main part of the script here...

my ($parm1,$parm2,$parm3,$parm4)=@ARGV;

func1($parm1,$parm2)
$func2($parm3,$parm4)

exit(0);

sub func1{
#logic here.
}
sub func2{
#logic here
}
|
| etc
|

##</code><code>##

package Cart;

sub new {
   shift;
   my $self={};

   bless $self,"Cart";
   return $self;
}

sub doCart { 
     my ($self,$parm1,$parm2,$parm3,$parm4)=@_;

     # main part of original script goes here
}

sub func1{
}
sub func2{
}

1;

##</code><code>##

#!/usr/bin/perl -w 
use strict;
use lib qw @ /path/to/directory/my/binary/runs/from @;
use Cart;

my $cart = new Cart();
|
| hand waving
|
$cart->doCart($arg1,$arg2,$arrg3,$arrr_ahoy_matey);
|
| etcetera...
|

##</code><code>##

use FindBin qw/ $Bin /;
use lib "$Bin";
| etc