Your question is a little unclear to me, but lets assume that you only want to match on (and return) the 3rd "word" in each line.

Then you could do something like this:

#!/usr/bin/perl -w
use strict;

while (<DATA>) {
   my $string = (split)[2];     # extract the 3rd "word"
   print "$string\n" if $string =~ /^[gH]/;     #output if it begins w
+ith a "g" or a "H"
}

__DATA__
data to gbsdff03dfif7 is
data to HR620-Asdf2
data to HP650dfgd-Af452 is
[download]

Cheers,
--Darren :)