I don't think C supports regular expressions natively. You'd need a regexp library for that. Here are some I found. http://www.tropicsoft.com/Components/RegularExpression/
http://sourceforge.net/project/showf...ackage_id=8041
http://research.microsoft.com/projects/greta/
I'm not sure if the last one is free. As for how to use them I guess they should come with documentation.