Hi,
You don't need to create the mount point, it will be created automatically
when you connect to Icecast with valid login credentials.
Assuming you want to play files in Winamp and stream them to Icecast, use a
plugin like Oddcast (http://www.oddsock.org/tools/oddcastv3) and configure
it to connect to your Icecast server. Specify the desired mount point in
Oddcast, along with the relevant password. Then hit Connect and start
playing your files in Winamp. All being well, you should be able to tune
into your server and hear the files being played.
Hopefully this is what you want to do, give us some more information about
what you want if it isn't.
Geoff.