Grep Gzipped files

Greetings Perl Experts,
This is not a homework assignment.
I want to use gzgrep within a perl script.  I have written the following:
====Begin code.pl
#!/usr/local/bin/perl
use strict;
#use warnings;
use FileHandle;

#my $gzgrep = "/usr/bin/gzgrep";
##my $GZGREP = '/usr/bin/gzgrep';

my @sourcefiles = glob("source*.trace.gz");
#print "@sourcefiles\n";

foreach my $sourcefile(@sourcefiles) {
   #my @vsrtracelines = $fh->getlines();
   my $patterna = "AlphaBetaGamma\(4, 0\) ";
   my @patterna = system "$gzgrep $patterna $sourcefile" ;
   #my $results = `gzgrep $patterna $sourcefile`;
   #print "@patterna\n";
   #print "$patterna\n$gzgrep\n$sourcefile\n";

   my $tfilelist = "$sourcefile.txt";
   $tfilelist =~ s/source\.{1}(.*)0000-0400\.trace\.gz/$1/gi;
   my $fh_out = new FileHandle "> $tfilelist";
   #print $fh_out "Total connections for $sourcefile\n";
   my $pattern1 = " ";
}
===End code.pl
Neither of my gzgrep attempts are working.  
TIA for your help.