Few days back i posted about CAML Builders here is an updat You can download version 184.108.40.206 from our UTU.com that is offical site of Patrick Tisseghem. The Author of CAML builder. Good news is that the Paramerts length zero bug is fixed.
If you never heard about Excel Web Services then you should. And if you already know how to use Excel Services then you should know that you can use an Excel Sheet on MOSS as webservice too. Here is a Web Part that uses Excel Sheet as Webpart and the article below show how to develop and deploy such webparts.