Zipping & Unzipping files using command line

We are looking for a command line to generate zip file & extract files from a zip file. More prominently – unzipping files using the command line.

A couple of points –

1.      We cannot opt for any freeware or paid-up utilities like ICSharp, GZip, 7Zip, etc.; even wzzip.exe command comes at a price.

2.      Windows (probably 2003 onwards) itself contains a utility which zips files and extracts from zip file – any ideas on command line to this are more welcome J