Is the DNN security system (membership provider) separate enough that I could use an external database for authentication?  If so, how would I do that?

For example, I have a separate database with all the aspnet* "stuff" in it (i.e. all the user/role information - the SqlMembershipProvider data).  I would like to direct my DNN install to use it rather than the database it's using for everything else.  Is that possible?

I assume it can't be as simple as changing the "SiteSqlServer" connection string in the "web.config".

Thanks!