I want to create vba code that modifies the categories in a calendar view
filter for outlook 2003.

I was expecting categories to be somewhere in the object structure as an
object property but it seems thay are buried in the XML property. Searching
for advice on XML turns up lots of articles on how to edit XML by hand but I
want to do it programmatically.

Are there a set of routines somewhere that simplify the task of modifying
properties buried in the XML property of an object?

Alternatively is there some other way to modify these properties such as the
categories in a view filter?