Features / Usability

is there a way to conect the tikiwiki database to another, non tiki database?
if i have another server and i want every user registered in that server to be automaticaly registeren in my tikiwiki database?
of course i'm not expecting that someone tells me how to control my other database, but what must a program do to enter new users in tikiwiki?
if i can write a program that reads the users from one database and adds them to the other, in what form would it need to write?

thanks