A Powerful New Microsoft Excel Feature

I'd love this one. How many years before we get this one?

There's a spreadsheet I maintain at work. Some of it is private, some of it not. What I'd like is to be able to access the private stuff from home. That's the origin of the problem, but not overly important when it comes to saying what I want.

I want to open ONE excel file.

But, I want this act of opening this file to effectively open MULTIPLE files. Yes, the file I GO TO is the master dashboard - it loads up the other files and what I look at looks like one Excel workbook, that is saved in distributed fashion.

I'm sure there are hoops one can jump through to achieve the end result, but I want it packaged nicely.