Move sub nodes into parent attributes with XSLT

Question

I have some XML which contains records and sub records, like this:

Answer 1

This might do it, run this following snippet of XSLT when processing the top level elements:

Essentially this iterates over each sub- element and creates an element describing the desired attribute. The position() function is called to get the relative position within the top level element: 1, 2, 3, etc.

This is not a complete solution; some familiarity with XSLT is assumed.