Intercepting XSL datasets

Hey everyone,

I was wondering how it might be possible to intercept the datasets that the XSL sheet uses and modify the data before it gets transformed?  In the XSL file, it seems to reference several datasets and the one I'm interested in modifying is //GetOrderDetailsInfoResults/Payment.  Can I somehow get access to that dataset from the aspx file and modify the rows based on some criteria so that those modified values are displayed after the transform?

Hopefully I'm being clear enough, thanks in advance!

Sean