How to compress and extract files?

hi
i need help in my project i need to compress a group of files (in project this file will be dicom files and text file and other types of file )and the resulted file will have unique extension(like .medo for example) and my program only will read this archived file and write on the files inside compressed file how can i do this plz every one read this message send to me solution bcz i in big problem and thanks alot