To summarise and breakdown your questions - I've made some assumptions and answered it below:
If you want to create reports from the Metadata repository - this should be "doable"
If you want to export a report into an excel spreadsheet - this is possible
How you would do this depends - but a overview solution could be -
Analyse the data model and the data
Create a report (probably a webi report on a unx)
I've seen cases where you could combine Audit data from auditing database to give additional information on the usage.
It's easy to export webi report into excel
