passing email address from a form

I have a formmail script, but am trying to pass the recipient value into it 
from the external form.

type="hidden" name="recipient" value="someone@somemail.com"

I tried:

my $field_name_email   = 'sendtoemailaddress';
my $destination   = "recipient";
$SendTo{'copies'}      = 'fvs01@sleepyfrog.com,';$destination;

But obviously wrong!

Any help would be really appreciated