[xsl] How to convert day-of-month with xslt 2.0

[Manfred Staudinger <manfred.staudinger@xxxxxxxxx>]

Hi list,

I've done this with xslt 1.0 (awfull, but works), but with
all the possibilities of 2.0 I'm a bit lost how to do this:

input      output
6               06
16             16
(2)             02
(23)           23
otherwise   00

Manfred