[xsl] Creating a padded sort key: easier from elt sequence or string?

[Yves Forkl <Y.Forkl@xxxxxx>]

Hi,

I'm lucky to be able to define some XML structure largely according to 
the needs of (XSLT) processing.

I have strings of variable length consisting of numbers and letters 
separated by dots, like "3.11.A.9" or "3.2.B.7".

Each of these strings shall take the role of a value for a sort key, but 
only after padding each number with sufficient zeros in order to sort 
"3.11.A.9" after and not before "3.2.B.7" (then "3.02.B.7"). The letters 
are always single letters, and the numbers have no more than 3 digits.

My question is as follows: which XML representation is more convenient 
when trying to fulfil this task in XSLT 1.1?

1) a PCDATA element containing a string like the ones above

2) an element containing a sequence of PCDATA elements, one for each of 
the numbers and letters (the dot in between may be added during processing)

And what's the best way of going about implementing the creation of the 
padded sort keys in XSLT from the more favorable representation? Would 
the solution differ much in XSLT 2.0?

Any hints are very much appreciated.

 Yves