Need help modifiying this script

I use the following script to create a simple web interface that allows users to run some basic commands on a cisco router. I need to modify it to allow the user to imput some values.

For example this script will allow a user to run the command(by selecting it from a drop-down menu) "show cable modem". I want to add the funtionality for the user to be able to input a specefic cable modem MAC address.

So the user would select the commnad to run (from the drop down) and then be promted for the MAC address to use with the command.

Her is my current code:

#!/usr/bin/perl

use strict;
use warnings;

use CGI;
use CGI::Carp qw/fatalsToBrowser/;
use Net::Telnet;

my $q = new CGI;

open FILE,"/inetpub/wwwroot/_vti_script/cmdlist" or die "Can't open cmdlist $!";
chomp(my @cmdlist=grep{/\S/}<FILE>);
my %cmdlabels;
@cmdlabels{0..$#cmdlist}=@cmdlist;
close FILE;

print $q->header,
        $q->start_html ('IP Engineering'),
        $q->start_form,
        "Select CMTS: ",
        $q->popup_menu('ip', get_ip_list()),
        $q->popup_menu(-name=>'cmd',
                       -values=>\@cmdlist,
                       -labels=>\%cmdlabels,
        ),
        $q->submit,
        $q->end_form
    ;

print '<hr>',
      '<h2>Here Are Your Results For: ', $q->param('ip'), '</h2>',
      '<pre>',
       get_config($q->param('ip'),$q->param('cmd')),
      '</pre>'
       
  if $q->param('ip');

print $q->end_html();

sub get_ip_list {
    my $myfile="/inetpub/wwwroot/_vti_script/iplist";
    open FILE, $myfile or return "<strong>Error opening ip list $myfile: $!</strong>";
    chomp(my @ips = <FILE>);
    close FILE;
    return \@ips;
}

sub get_config {
    my $ip = shift;
    my $cmd = shift;
    if( $cmd < 0 || $cmd > $#cmdlist ){
        return "<strong>invalid command</strong>";
    }
    my $t = Net::Telnet->new(Timeout => 240,
                          Prompt => '/.*#/',
                          Host => $ip);  #warning: $q->param('ip') returned from the user could be anything, so they could be tricking you into connecting to any host
    $t->login('xxxxxxx','xxxxxxx');
    $t->cmd("terminal length 0");
    #my @lines = $t->cmd($cmdlist[$cmd]);
    my @lines = $t->cmd($cmd);


    $t->cmd("");
    $t->close;
    return @lines;
}