flash actionscript: are there functions in flash that search strings for regular expressions, of something of the like? if not, then is there a way to implement such functionality?

Just do a quick search on google groups:
http://groups.google.com/groups?hl=en&lr=&q=group%3Amacromedia.flash.actionscrip
t+regular+expressions&qt_s=Search

According to Jeckyl, AS3 should be in Flex 2 and so it should be coming to
Flash soon. But there are scripts you can find... but they will be fairly slow.