You may consider a free tool such as RVTools from robware that will put all the details in a spreadsheet for you already. Get the client familiar with this output and run the reports ad hoc when needed to check progress.
If you really want to go the dynamic spreadsheet route you will have a bit of learning curve if you don't already use Excel features such as Pivot Tables and vlookup, etc. Either way, the RVTools report can feed your custom solution or stand on it's own. Ideally you should be investing your time in PowerCLI instead of Excel IMHO 
RVTools Download:
http://www.robware.net/