[Sigia-l] Dublin Core "Sort key" field

[MJJAIXEN at up.com]

For our search engine, we are using metadata based on Dublin Core for
tagged keywords, titles, descriptions, and update/create date information.
We have one section of content where we'd like to allow people to sort
results on a key field, which in this case happens to be numeric.
Normally, I'd just sort on title, but since it's numeric, I need to make
sure that 6 comes before 42.

What I was going to do was to populate a metadata field with a "sort key"
value that would typically default to the title, but in the case where it's
numeric, would pad the field with leading 0's so the sort would work.
(i.e. 6 would become 006, 15 would become 015, etc.)  I can define an
internal custom field in our metadata framework, but if there is a
more-standard way to do this within the Dublin Core framework, I'm all for
trying to follow standards.