You can certainly do it with XML, but it's unlikely you'll be able to make this work with a spreadsheet. The save as XML functions Microsoft provides for Excel do not create simple clean files.
You didn't mention what verion you're using of UCCX. I'm going to assume you're working with one of the Windows based versions. It shouldn't matter terribly much, but some of the version 8 and later stuff is a little different.
Go here:
http://www.cisco.com/en/US/products/sw/custcosw/ps1846/products_user_guide_list.html
Find your specific UCCX version, and pull down the Scripting and Development Series volume #1 for your version. In the bookmarks in the PDF, find the one that says "Designing a Web-Enabled Client Script". This has a simple script that shows you how to do an XML query and select the data you need. Explainations are pretty good I think.