Extending Xforms schema

I know enough about XML Schemas to be dangerous and I am wondering if 
the Xforms schema specification is meant to do what I want to do.

I want to create high level groups of  controls or make custom controls 
that have special behavior. And I would like to have these special 
control definitions have their own namespaces and be able to use them in 
schema-validating XML editors - I want to be able to choose from a 
library of special control schemas. I would like for these controls to 
be valid anywhere that a standard Xforms control is allowed - within a 
"repeat" element, for example. Is the Xforms meant to be extended in 
this way or am I way off base here? If it is, how would I go about doing it?

Thanks,
Al

-- 
Al Byers
Automation Groups Inc.
777 South State Street
Orem, UT 84058
byersa@automationgroups.com
http://www.automationgroups.com