In addition to what ELISHEVA said about parsing, I'd offer that you're making a simple manual task into a more difficult manual task with an intermediate programming loop.

Double clicking on the first word in the Word doc and hitting Ctrl+b will do what you say you want and without the runaround of cutting, pasting, parsing, loading, copying, pasting. So, I'm wondering if this is really what you want (emphasize the first word of the doc) or you actually have a different requirement for which this is a stand-in.

If your requirement is real, I'd suggest doing something with OpenOffice or RTF instead so you could remove (all but one of) the manual steps; you'd probably have to export to RTF first or import to OO. Both could be scripted completely and Word will open either if saved correctly. This isn't really trivial though. Ctrl+b is, if a bit repetitive. :)