It's now called a night qualification and is a JAR thing. Doesn't depend on the licence you have. Not sure about what you mean regarding the dual instrument training; there is none stipulated for the night qualification, the course consists of 5 hours of which 3 must be dual (including at least 1 hr nav), 5 solo takeoffs and landings, one of which must leave the circuit and the balance can be dual or solo.
Unlike the night rating the qualification does not have to be renewed and is valid as long as your licence, the only thing is that if you want to carry passengers at night you have to have made one t/o and landing at night out of the 3 in the previous 90 days. Don't have documentation references at the moment, sorry. You could try
www.jaa.nl Cheers DB6