#!/usr/bin/env perl

use v5.14;
use warnings;

my @TFCNTL_Tax;

while (<DATA>) {
    $TFCNTL_Tax[@TFCNTL_Tax] = (split)[8] =~ y/$,//dr =~ s/^(.*)-$/-$1/r;
}

say for @TFCNTL_Tax;

__DATA__
0 0 0 0 0 0 0 0 $1,234.56 0
0 0 0 0 0 0 0 0 $7,890.12- 0
0 0 0 0 0 0 0 0 -$3,456.78 0
0 0 0 0 0 0 0 0 $-9,012.34 0

##</code><code>##

1234.56
-7890.12
-3456.78
-9012.34

##</code><code>##

    $TFCNTL_Tax[@TFCNTL_Tax] = (split)[8] =~ s/[\$,]//gr =~ s/^(.*)-$/-$1/r;