Is there a way to create a field that would dynamically link campaigns together in a parent/child wa

I am using eMOD and we have several campaigns based off a single recommended campaign template supplied by our Marketing team.  When I create these 'child' campaigns I need a way to tie them back to the parent template campaign that is setup. There is no way to do that in eMOD and I am thinking of creating a custom field that would pull in a list of source codes from existing campaigns for me to select from.  I don't want it have to maintain the pick list values in the custom field manually, though.

Any help or suggestions would be appreciated.