format numeric values as comma delimited strings

Question

Hi,

How do I format numeric values as comma delimited strings?

These data are returned to me as XML. I transform it using XSLT, and present it as html. But I need to format these numeric values the way the client wants it.

e.g.
12345 => 12,345
1235.12345 => 1,234.12345
13.3566 => 13.3566
132341.00 => 132,341.00

I've been playing all day with FLOOR, money, string manipulation but I still can't find an answer to my problem.

Any help would be greatly appreciated.

Thank you very much.