Tim,

Check out these MSDN articles.  I think you want to specify the optional
Access parameter for the default property.
http://msdn2.microsoft.com/en-us/library/envdte80.codeclass2.addproperty(VS.80).aspx

It also appears that the CodeClass2 has no way of controlling where the file
lands in the physical structure, but this is a guess based on the
documentation.  In fact, in the sample, the class is being added at the
selection of the current document.  Maybe you need to create the document
first, where you want it, and then design the class?
http://msdn2.microsoft.com/en-us/library/envdte80.codeclass2.addclass(VS.80).aspx

Hope this helps,

Steve - dotneticated.com