Can I combine target lists?

[bradym80]

I have one campaign that is sent out to four target lists. I would like to combine all these lists into a single list for easier management. I am having a problem similar to the one posted here:
http://www.sugarcrm.com/forums/showthread.php?p=120328

To summarize, when adding contacts to a campaign via the "Manage Subscriptions" button in the contacts edit/view, the user cannot be added to a target list, only an email campaign. if a campaign has more than one target list, the contact will be added to any target list at random. In my case, the contact was added to a target list meant for employees's (not a test list). Luckily I caught this.

Is there any way I can combine lists? If I export my lists, merge them, then reimport, will it preserve existing relationships through out the application?