I am forwarding the post of Chris sent under a different subject title, so that I stays under the same subject title, for easy tracking:

Chris wrote:

Dear Dan,

you'll get an email this evening proving that OOo stores hyperlinks as %20 coded URLs.
And now, I looked at word in detail:
If you make an hyperlink in word and press alt-f9 you see that it is stored in a proprietary format (well, no wonder): HYPERLINK "O:\\Daten\\Eigene Datenquellen"
but if you export to htm filtered for example, you get

<p class=MsoNormal><a href="../../USER/foltin/Daten
/Eigene%20Datenquellen">O:\Daten\Eigene
Datenquellen</a></p>

So, word doesn't use URLs internally for storing file references.

Best regards, Chris