[Zope] Accessing Zope DA connection from external method

Jpenny wrote a little how-to about accessing ZSQL Method from External Method. This has really whetted my appetite. At the moment, my external methods create and destroy their connections to the database whenever they are called. This can potentially be expensive when scaling up. Can anyone point out how do I reference a Zope DA Connection from an external method. This way I can make use of an existing open connection instead. Thanks in advance Chui