Reputation function in q&a plugin

Hi, I wouldl ike to know which is the function for reputation management and how it works cause I would like to integrate cubepoints wp plugin http://cubepoints.com/ with q&a

I found
function qa_get_user_rep( $user_id ) {
return (int) get_user_meta( $user_id, '_qa_rep', true );
}

but I havent found the insert functions

thanks a lot
Stefano