Migrating plugin data

Hi,

I am currently setting up a multisite network and a few of the websites that will be migrated are already using wordpress. I know I can import/export posts, pages, comments and so on. But can I do the same for plugins that have been used. Specifically MailPress, TDO Mini Forms & Event Espresso. They have quite bit of data I don’t want to lose. How do I go about doing this?

Thanks!

Dana