Scripting Metapackage of PackageMaker

Hi! Does anybody have any idea how to automate the creation of metapackage of PackageMaker? I really am interested in knowing since I have this bundle of single packages that I have to put into one Installer package. :cry: I have already created a script for single packages but packagemaker command does not support metapackage. :frowning:
Any hints or ideas are greatly appreciated. Thanks.