Importing users into buddypress

I have a list of people who signed up to our community at an event. I want to import their data - including some x-profile data - in to buddypress.
I would like to be able to upload a password for them so I can send them a welcome email containing their temporary password, their username and some other information from the event.
I have tried a number of different CSV upload plugins, but none seem to work. They either do not upload at all, or they upload wordpress users, but they are not findable in the buddypress areas of the site.