Import requirements, one row per requirement

I do pre-planning in a spreadsheet, to get initial agreement on what the different features and requirements are. This takes the form of one row per Requirement, with a column to link each Requirement to a particular Feature. I would like to be able to import this spreadsheet into Aha, and have the Features created (if they don't already exist), and the Requirements created inside it.

This should include importing any information about each Requirement, including custom fields.

The current Feature import mechanism, where you can have columns for Requirements, is not suitable for this use case.