DWG to XML

Hello,

now I've a problem, that I have to solve.

I got several ACAD 2000 drawings, and it is necessary to convert them to XML-format (for next users).

The constructor, who transferred these drawings told me, that only ACAD 2002 and obove supports XML, but in his office they are now using

My question: Exists there any tool or gives ther any way, to converts DWG-data in the XML-format without loosing the 3d informations (BTW i've tried via PDF but IMHO this way 3d is lost).

Thanks for any response...