Write DataSet as XMLDataDocument without Expression entries?

Hi!

I use an ADO DataSet with DataTables having lots of columns using
expressions (mainly for the purpose of making visible Master entries in
Detail tables).

The DataSet is linked to an XMLDataDocument in order to write the current
data to XML. I observed that entries in columns using expressions are also
written to the XML file, although this creates a lot of redundancy (Master
entries being replicated over many Detail entries).

My question: Is there any way to prevent this (besides doing everything
manually)?

Thanks for any hint!
--
Axel Hecker