Zip on a fileserver

Hello, I have the following problem. I build a box for fileserving with nfs. No user is allowed to login directly to the computer, but some user wishes to use programs like zip to compress their data. They zip their data on another box which means, the data are transferred to their box which zips the data and then the data are transferred back to the server. This solution is naturally not the optimum, because it cost a lot of time and raises the network traffic. Now my question is: Is it possible to allow the users to zip directly on the server without giving them the possibility to log in. regards Guido