What am I doing wrong?

You are not showing the full script. See SSCCE.

Here's one showing how it works:

$ cat show.cgi 
#!/usr/bin/perl
use strict;
use warnings;
use CGI;

my $store = CGI->new;
my $cell = $store->param ('cell');
my $td = $store->param ('target_dir');

print $store->header (-type => 'text/plain'), 
    "Cell is $cell and Target Dir is $td\n";
$ ./show.cgi cell=1234 target_dir=/foo
Content-Type: text/plain; charset=ISO-8859-1

Cell is 1234 and Target Dir is /foo
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