>Here is what has not worked yet . ..
>

>CREATE CLASS mymultimedia  of MyLib AS _multimedia
>CREATE CLASS mymultimedia  of MyLib AS _videoplayer
>CREATE CLASS mymultimedia  of Multimedia AS _videoplayer
>CREATE CLASS mymultimedia  of _Multimedia AS _videoplayer
>

You don't have to invent anything in this case, just read help :)

CREATE CLASS MyVideoPlayer OF mymultimedia AS _videoplayer FROM _Multimedia