Forum Discussion
Export MS Project in HTML
As far as I know you won't find anything in the Microsoft suite of applications that does what you want but a quick web search finds several third-party applications that claim to do what you need/want. You might want to check that out.
As far as a basic export of Project field data to Excel, there are better ways than copy/paste. The first is an export map but one thing an export map will not do is to preserve the full content of extended text in Project's Notes field. To work around that limitation, several years ago I wrote a macro for exporting Project data to Excel. You can check it out in this Wiki article:
But, as you already noted, the spreadsheet in Excel is a flat file. In order to include a feature to allow expanding/collapsing summary levels a macro in Excel is required.
John