Tapes or DVD's

Does anybody know the name of a movie I'm
looking for ? It is suppose to be a ninja/
martial arts film and it was promoted as
such. I think it even has ninja in its
title, and the opening credits have martial
arts style graphics. Basically, its a British
Commando type film. I think it was made in the
1980's. A singer is taken from her club to
a castle-fortress in Eastern Europe, and these
British commando types make a rescue. There is
a lot of slow-motion machine guns and explosions.
Does this ring a bell ???