Batch Audio files

I need a utility that will allow me to batch append a single audio wav file to a directory of mutiple wav files.? This utility will be able to merge a directory of 500 "hello" wav files with a single wav file. The result would be 500 new wav files that combined the both together. Example: I have 500 wav files named: [login to view URL] ? [login to view URL] [login to view URL] [login to view URL] when you play each file.. it plays "Hello Andy" or "Hello Aaron". I have one main file called "[login to view URL]" which plays "Welcome to our website.." I want to combine all my intro files with the message so the final output will be named the same as the original but when you play it... you will hear "Hello Andy...Welcome to our website"