How can I copy elements from a key and add an attribute to every copied
element containing its position in the sequence.

E.g. The key "contains" 3 my-include tags:
<my-include src="a"/>
<my-include src="b"/>
<my-include src="c"/>

As output I want
<my-include src="a" position="1"/>
<my-include src="b" position="2"/>
<my-include src="c" position="3"/>

regards,
--
Joris Gillis (http://www.ticalc.org/cgi-bin/acct-view.cgi?userid=38041)
Vincit omnia simplicitas
Keep it simple