package ConfigFileRead;
...
use vars qw(%User_Preferences);
...

##</code><code>##

# main program
...
require ConfigFileRead;
use Data::Dumper;
print Dumper \%ConfigFileRead::User_Preferences;

##</code><code>##


# in ConfigRead.pm
sub readConfigFile {
    ...
    return \%User_Preferences;
};

# main program
my $config = ConfigFileRead::readConfigFile();
print Dumper $config;