Why not use a hash instead of those icky scalars? Make life simpler:

my %titles = (
   'suby' => 'submitted by',
   'stat' => 'Status',
   'desc' => 'a short concise description',
   'catg' => 'Jobfail',
   'agrp' => 'finance',
   'lnam' => 'Stevens',
);

# You'll likely want an array of these, but that's another post :-)
my %data = (
   'suby' => 2,
   'stat' => 7,
   'desc' => 8,
   'catg' => 536870915,
   'agrp' => 536870922,
   'lnam' => 536870926,
);

my @fields = qw(suby stat desc catg agrp lnam);

$tkt_data = join ',', map { $data{$_}, $titles{$_} } 
                      grep { defined ($data{$_}) } @fields;
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This is just off the top of my head so there are probably all sorts of typos and what not. The last line grabs only those keys of the hash that have defined values, then maps that to a list of two elements: the data value and its corresponding title. Then it's all joined with commas.