#!/usr/local/bin/perl -w
use Data::Dumper;
my @lines = (
   'lukeskywalker 444-333-2974 A      sum 20.0860 ZYX-237',
   'austinpowers  57240437     ZQFMR  sum 21.3820 HRM4922',
   'jedclampet    HNG-47255    MLP92  sum 14.2043 QRZ4993'
);

my %data;
foreach (@lines) {
        /^(\w+).*?sum\s+([0-9.]+)/;
        $data{$1} = $2;
}

print Data::Dumper->Dump([\@lines, \%data], ["*lines", "*data"]);

Output
@lines = (
           'lukeskywalker 444-333-2974 A      sum 20.0860 ZYX-237',
           'austinpowers  57240437     ZQFMR  sum 21.3820 HRM4922',
           'jedclampet    HNG-47255    MLP92  sum 14.2043 QRZ4993'
         );
%data = (
          'lukeskywalker' => '20.0860',
          'austinpowers' => '21.3820',
          'jedclampet' => '14.2043'
        );