Portability with using the Excel object?

Question

Hi.  I have an app that uses Excel.Application.  On my dev box, which has Office installed, it works great.  I want to move it though to a server.  We don't like installing stuff like Office on our production servers, so that is a bit of an issue with an app that wants to be able to speak Excel heh.  I was hoping since it compiled and had Interop.Excell.dll and Interop.Microsoft.Office.Core.dll it would just automagically work but no such luck.

Anyone know if there is a way to register something on the server to give the Excel functionality, or do I just have to suck it up and install Excel?  Thanks.