Mapping Lego parts to library

[karen lauro]

The Lego Power Tools book states parts are named #LEGOreferencenumber#. These are stated to be the numbers printed on physical blocks. I am assuming these are the same numbers Lego uses in instruction manuals.  Going to the top brick in Lego friends 41007, the number is 4113261, a 2x2x2. I could not find 4113261.dat in my LDraw\parts directory of the parts tracker online. So I looked for 300101 a 2 x 4 x 1. Could not find that either. What am I doing wrong? Thanks.