Pedja

Hi there.
I have a problem. When I change the default icon for some file extension, I need it to happen instantly. For example, I want to change icon for .cdc files. I know how to do it, and that is not a problem, but the problem is that it doesn't happen instantly, but when some kind of system refresh happens. I think it has something to do with shelliconcache.dll or iconcache.db, witch i can't find on my system. I have WXP Professional.
For example, when you start BS Player and assign it to be the default player for some file types, it happens, and all icons change right away.
I need to know what I can do to make this change happening when I want it. What is the thing that BS player and Windows Media Player do when they make a registry change, to make it happen at that exact moment?
The thing is that i am creating an application that should be able to do this, and i have no idea what should be done, and how BS Player does it.
Maybe I need to send some kind of system message to tell the OS to reload icon cache.
Any help would be most appreciated.
Thanks.