Question: How do you force excel to open a document in a new instance
Answer:
C:\Users\[*your user name*]\AppData\Roaming\ Microsoft\Windows\SendTo
Create
a shortcut from the excel executable. For me (Office 2010) this is
located here C:\Program Files (x86)\Microsoft Office\Office14\EXCEL.EXE,
Call the shortcut “Excel”.
Now you can open the Excel-files by right clicking on your document > send to > Excel