package Somepackage;

use Exporter;
our @ISA = qw(Exporter);

our @EXPORT_OK = qw($SOME_VAR);

our $SOME_VAR = 123;

1;

use Somepackage qw($SOME_VAR);

print "It is: $SOME_VAR\n";

##</code><code>##


##
## BEGIN makes available the variable $SOME_VAR, these declarations are
## read from a database in reality.
##

sub BEGIN
{
	my $varName  = 'SOME_VAR';
	my $varValue = 123;

	##
	## Dynamically create the package
	##

	my $code = qq/
package Somepackage;

use Exporter;
our \@ISA = qw(Exporter);

our \@EXPORT_OK = qw(\$$varName);

our \$$varName = $varValue;

1;
/;

	print $code, "\n";

	eval $code;

	##
	## Leaving out this line makes the "use Somepackage qw($SOME_VAR) fail (Can't locate package
	## Somepackage.pm in @INC ...).
	##

	$INC{"Somepackage.pm"} = 'abc';
}


##
## Let's use it.
##

use Somepackage qw($SOME_VAR);

##
## And see if it's defined.
##

print "Var is $SOME_VAR\n";