I personally don't know of a quick way to do this. If you know how to program you can write an application that changes the database behind the scenes prior to the report loading. Otherwise you have to make 80 copies of the report and do a "Change Data Connection" for each one. CR automatically switches the fields names over and if a field name doesn't match with the new database then it lets you tell it which field to replace it with.

Yes it's in 8.5. I have no idea which menu item to use in 8.5, but in XI you would do the following:
From the menu, choose Database | Set Datasource Location. Click on the database (or individual table) you want to replace and in the other window find the database (or table) to replace it with. Then click the Update button.

Hope this helps.