Help, How to get Stylesheet Source Locator in an Extension Element

[John Gentilin]

I am trying to determine the Stylesheet source location in an
extension element so when I throw a TransformerException the 
Debug output is correct. I am using the elem parameters as the 
Source Locator but the line number and column number are always 
coming up as 0.

What is the proper way ??

Thanks
John G