Exporting Global Address bk in Exchange5

I need to export the GAB in exchange 5. I know this can be done, but i need to be able to automate this procedure from a command line or something as this will be something that is run nightly. I need to be able to compare the GAB to a database that runs our intranet. Does anyone know of a way to do this, or to simply export the GAB to a text file or something?