package Parent;
require ('./parent.cfg');

package Parent::Child;
@ISA=('Parent');
require ('./child.cfg');

package Parent::Child2;
@ISA=('Parent');
require ('./child2.cfg');

package Parent::Child::Grandchild;
@ISA=('Child');
require ('./grandchild.cfg');


##</code><code>##

$config={
	string=>"bla",
	array=>['val1','val2'],
	hash=>{
		foo=>'bar',
	},
# etc, put any valid perl data structure here	
};

##</code><code>##

in parent.cfg
#...
    list=>['val1','val2','val3'],

in child.cfg
#...
    list=>['val1','val2','val3','FOO','BAR'],

##</code><code>##

parent.cfg:
%config=(
	# complex data structur
)

child.cfg:
config_add('newval',$datastruct);
config_remove('DontNeedThisHere');
config_push('array',$newval,$anotherval);
# and some other data manipulation routines