String Handling in XSLT

Is there anyway to do string handling (such as only displaying the last
four numbers of a credit card). It's not a problem to change the code that
generates the XML doc to make the credit card element just contain the last
four numbers of the card, I was just wondering if there's a way to do it in
XSLT, perhaps a list of string handling functions that are supported?


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list