You cannot create the datasource through XDoclet. Look at the end of section 4.4 and all of section 4.5 for hints on creating your connection pool - http://www.amitysolutions.com.au/downloads/response_tester.pdf.
Look at http://www.amitysolutions.com.au/documents/JBossJNDI-technote.pdf for information on configuring your deployment descriptors to refer to the datasource. You'll also need to examine conf/standardjbosscmp-jdbc.xml to see how EJB 2.0 compliant CMP refers to the datasources.
Hopefully that will get you a start.
Really, thank you.