Importing personal list to global list?

Im a young new NetAdmin (for now). For more than a week me and my colleagues have been trying to import a personal distribution list to a global one. We know you can type them all in but, its 2001 there has to an alternative…something automatic. The most obvious question is whether or not its even possible? Secondly, why is it not documented? I am in need of help. Lets create this virtual braintrust and crack this caper…