This method can be tailored to use Winzip for zipping or unzipping files within SQL Server (SPs, DTS Packages ...)
Pretty easy to do BUT you will need to buy a licensed copy of WinZip ... and as often as EVERYONE uses it ... its worth buying a copy just once - LOL.
You will also have to download the current version of the WinZip Command Line interface from their site.
The reason for the license is that when you register Winzip, it removes the commercial/company header message from being displayed when you run Winzip in the command line. If you do not register the software, the Unzip will hang. So in say that ... here is the code to unzip a file thru SQL Server ...
What the code is doing above is starting WZUNZIP that has been installed in the C:\MyDir folder. It is Unzipping a zipped file called MyZipFile.zip which was passed in as a variable. It will unzip the file to the C:\MyDir folder.