Exporting from ER Studio to UML tool like MagicDraw

Has anyone successfully exported a data model and imported into a UML tool like Magicdraw?  Our ultimate goal is to produce and OWL.  So exporting to an RDF format would work as well.  

The UML-XMI exporter produces much of the information we need but is loses things and is not always correct – we can’t get all the information out we need, particularly in support of relationships and reference values.