From looking at this article on xml.com you may want to look at Sleepycat::DbXml. I could not find it on cpan, perhaps it comes as part of the download from sleepycat. Take a look at the article for some example code and have a look around on Google for further resources.
Hi Martin, thank you for your time to look for the answer. Before posting the question I googled a lot about the topic, I read the article you mentioned, but I came to the wrong conclusion, that Sleepycat::DbXml is a hipothetical module, because I could not find it on CPAN either. I doublechecked and found it bundled with Berkeley DB XML in:
Berkeley DB XML 2.2.13/dbxml/src/perl/DbXml/
Did you check out the Sleepycat Developer zone? They have a mailing list and a newsgroup you could read/ask about using Perl with this product on if you have not done so already.