ICM.MP43 CODEC

I’m trying to play a movie in RealPlayer. When I try and play it, it says an error occured, and it says it doesn’t support the ICM.MP43 codec... So anyway, does anyone know where I can find the codec for it. So the movie will work in RealPlayer. I already downloaded the DivX one, that works fine for some movies... But not this one. Thanks.

This should have it
http://www.microsoft.com/windows/windowsmedia/format/codecdownload.aspx

If not, try this http://www.undercut.org/msmpeg4 (click on installation package)