DTD to XSD converter

Hi,

I'm looking for an DTD to XSD converter tool written in Java and being able to be invoked from command line; I would like to execute it from an Ant task.

dtd2xs v1.0 (by Joerg Rieger) generates "xs:import namespace" and separate "xs:element" for primitive types. This does not comply with our requirements.

XML Spy generates correct XSL but is not written in Java.

Any other idea? Thanks in advance your help!
SB