Thanks for the quick reply! Yes, I was already aware of the possibility to achieve this using Winamp/Sonique/Media player etc and have experimented with these (to my mind Sonique is best), but they are quite crude for my purposes. Now, I know that specialized software exists (I saw a media announcement some time ago which stuck in my mind) but I have no idea what it's called or where to get it. With a bit of luck someone else will have some idea of where to get this software.
Thanks again for the reply, see you around.