Converting Flat file to XML and XML to Flatfile in COBOL

Hi,
I have a requirement like this:

1.When an XML file is received from another system, I need to convert
it into a flat file and then update the DB2 tables in my system.

2. Create a flat file from DB2 tables and convert it into XML file to
tranfer to the other system.

I don't have any tools and I need to do this using COBOL. If any one
know how to do this, please let me know.

Thanks,
Raya.