ASP.net (vb) GZIP

I have a requirement for a class or namespace writing for my asp.net (vb)? website as follows: I have a folder with several hundred xml files zipped using gzip, a need a class or namespace that contains a public function, whereby I can pass a string variable that contains the full local path to a file, the function will then extract the xml file from the gzip archive and place in a predetermind location. I will be writing a small piece of code which will retreive all the the gzip files, this code will then iterate through the file list and will then call the relevant function with each file as a parameter. Upon completion I require the entire source - no dll's.