So you're reading xml data that is created by some other process that you wrote, and you know what to expect. XML parsers are good, and I commend their use, but in your case, I wouldn't fault the use of regexes to parse it.

To get back to your original question, which is a data structure problem, a regex solution sort of like the following ought to work (and of course, filling the data structure via an official XML parser module should work in a similar way). I put this into a simple-minded harness to test it out -- you'll need to complicate it a bit, I'm sure.

#!/usr/bin/perl

use strict;
use Data::Dumper;

my %hash;
my $self = \%hash;

while (<DATA>) {  
    if ( m{<(\w+)>([^<]+)</\1>} ) { # a content element
        $$self{$1} = $2;  # store the content keyed by tag name
    }
    elsif ( m{<(\w+) ([^>]+)/>} ) { # an "empty" element
        my ($elem,$attr) = ($1,$2); # get tag name and attributes
        my %attrhash;
        while ( $attr =~ s/(\w+)="([^"]+)"// ) {
            $attrhash{$1} = $2;
        }
        push @{$$self{$elem}}, \%attrhash; # expect multiple instances
    }
}

print Dumper( $self );

# here's one way to access the structure's contents:

for my $tag ( sort keys %$self ) {
    if ( ref( $$self{$tag} ) eq 'ARRAY' ) {
        for ( @{$$self{$tag}} ) { # $_ is now an array element contain
+ing a hash ref
            for my $attr ( sort keys %{$_} ) {
                print "$tag : $attr = $$_{$attr}\n";
            }
        }
    }
    else {  # the tag had a plain string as content
        print "$tag = $$self{$tag}\n";
    }
}

__DATA__
<ObjectType>
   <AppObject>hello</AppObject>
   <AppObjectField>gender</AppObjectField>
   <valueTargetPair value="MALE" targetPo="Incoming 1" />
   <valueTargetPair value="FEMALE" targetPo="Incoming 2" />
</ObjectType>
[download]

You'll want to study up on the "perlref" (and "perlreftut") man pages, if you haven't done that yet.

update: jeffa's solution is of course the correct one -- having studied that (as I should have done sooner), I conclude that my own proposed code is unnecessarily complicated and obscure. Do be sure to notice that jeffa solved the problem you were having with references.