XML-schema subset defined using XML-schema

Hello,

I want do define a "schema language" that allow just a subset of the XML-schema data types.
It shall not be possible to use all the Simple Types built in to XML-Schema. The facet that may be applied to a certain datatypes should also be limited.

Is there any easy way to do this?

Could an XML Schema data type library be used?

Do I have to start the "XML Schema schema for XML Schemas" and make a similar one?

Can the redefine element be used to redefine parts of "XML Schema schema for XML Schemas"?

Any advices are appreciated!

Thanks,

Bo Johansson Ericsson Mobile Communications AB
E-mail: Bo.I.Johansson@ecs.ericsson.se