Exporting to word requires mapping of the xml from infoPath into word. In InfoPath 2007 this is a lot easier, but in 2003 it's hard.
Here is the easy (but not very user friendly if your doctor is th one to do the cut and paste):
http://blogs.msdn.com/infopath/archive/2004/04/29/123459.aspx
Here is the more difficult way:
http://groups.google.com/group/microsoft.public.infopath/browse_frm/thread/4dd9ccf463b4daef/6c46e40803cfb1ca?lnk=st&q=&rnum=1&hl=en#6c46e40803cfb1ca
that information is in the InfoPath 2003 SDK. The SDK should get you started, it's just rather time consuming to setup.
This type of work is the type of work that our company (Qdabra Software) does consulting on all the time. If you would like more information on how we might be able to help you, feel free to go to our home website for more information:
http://www.qdabra.com/ We have done work in the EMR/EMC field and do have some experience with solutionis for your industry.
Good luck!