[R] XML to R datafram or list

[shujf]

Hello all:

I am a new user of XML.  I need to convert XML files to R dataframes or
lists. The XML files were created by SAS 8.02 XML engine with options
xmltype=oimdbm  xmlschema=yes to keep user-defined format and SAS datetime
format.  Based on Duncan Temple Lang's reply to the post by Antonio
Pacheco (XML to Dataframe), there is no general way to read 
XML and convert it to a specific data format.  Do any of you by change
have a handler and an DTD or schema file for this case ready to share or
can you provide me any hints to write a handler?  Thanks a lot.

Jennifer Shu