Windows 10 Virtual Desktops and multiple program instances

I'm having an issue with the new Virtual Desktops in Windows 10. For example:

1. From Desktop 1, double click the file "test1.xlsx". This will open the file in a new instance of Excel (specifically 2010, in my case), on Desktop 1.
2. From Desktop 2, double click the file "test2.xlsx". This will change the desktop to Desktop 1 and open the file in the same instance of Excel as from step 1.

I've found this to also be true with Notepad++, so my guess is that this behavior occurs with any program that opens multiple files in a single instance. However, these are the two programs I generally use in this way.

I've found a number of ways to disable DDE for Excel, but this isn't what I want to do. If I open a second file from a desktop that already contains an instance of the program that should open it, I want to use that instance.

I've found manual ways of opening a second instance, moving it to the correct desktop, and then opening the file in that instance. However, the process is slightly different for each program and overall is, at best, clunky. Not to mention that now a third file will open in the most recently used instance, and not necessarily the correct one, requiring the whole process to start over again.

Solution 1:

I was excited about native windows support for Virtual desktops, but in the end, i still use Desktops for several purposes (ie. process which pops ups temporary windows that ends up in other desktop and so on). They don't work flawless as they did in windows 7, but still better then native win 10 solution, which is sad.