Custom Reporting

I have a client that needs to download cases and orders in the same report. Has anyone been able to successfully accomplish doing this either within the system as it is now or with an API? I am not sure why this feature isn't available - if the ability exists to add ecommerce functionality to a web form with custom fields, then there should be a way to create a custom report that shows all the fields the user submitted. Any suggestions or help would be greatly appreciated.