Ask user for arbitrary spreadsheet

[dougp]

If I right-click on the package name, I have an option labeled "Manage external data..."  This allows me to include a xlsx or csv file (maybe others) in the report.  Then the resulting package is saved to an arbitrary location.

In Cognos 10.2.1 I could have Cognos ask the user for the location of the file.  I still have a package or two that do this.  It's super helpful.

In Cognos 12.0.4 (and 11.1.x and 11.0.x) this is not possible.  The feature still exists -- I can include a spreadsheet with the source package -- but I can't make Cognos ask the user for the spreadsheet.  I seem to remember this was more of a browser issue related to security.  IE could do it because IE was, by definition, a security flaw.

So, now I have a report or two that ask the user for an arbitrary spreadsheet.  This is super helpful because if two users want to run the report at the same time but with different data, they don't clobber each other.

And, yes...  I responded to https://www.cognoise.com/index.php/topic,38363.msg125926.html#msg125926 with a possible way to do this.  But it turns out it doesn't scale well.  Once the data is more than trivial, my proposed solution fails.

Is there a good way to incorporate arbitrary data, provided by the user running the report, into a report developed in a modern version of Cognos Analytics running on a modern web browser?