I had to use a vector logo in Word once. It was a pain in the ass, and I ended up using a high res bitmap image instead. Google "vector MS Word" for more on the subject!

You might want to consider creating a standalone pdf with empty text fields to be filled in by your client. It can be done quite easily in Acrobat Pro, but you have to stick to fonts installed on the clients computer (if I remember correctly).

Windows WMF and EMF are vector formats. Just copy your Illustrator logo to the clipboard, and then in Word, select Edit > Paste Special > Picture (Enhanced Metafile). If Enhanced Metafile isn't an option, choose Picture (Windows Metafile). If both are available, EMF is better.

If you want to save the logo in .wmf or .emf format, there are any number of programs that will extract those formats from the clipboard.

Thanks. Copy pasting from Illustrator worked. The PDF suggestion is very helpful.