I'm not sure I understand your problem, because I think WMP's Library tab does look at your My Music folder.
In Media Player, if you click Tools>Options>Rip Music, you will see that you are able to specify the destination folder for ripped music.
If you specify
C:\Documents and Settings\Your Login Name\My Documents\My Pictures\My Music
then any tracks that you rip should be available on WMP's Library tab.
Is that what you wanted?