@fabyoga
First of all, I am not a Sharepoint specialist, my knowledge in this area is very limited, but this does not prevent me from giving you the information and modest knowledge available to me (information without guarantee).
As far as the link is concerned: Linking between different Excel workbooks is currently not supported by Office Online.
A link within an Excel workbook is possible. Additional Information
Differences between using a workbook in the browser and in Excel
Excel for the web looks a lot like the Excel desktop app. However, there are some differences to be aware of. For example, not all file formats are supported, and some features may work differently than the desktop app. This article explains these differences.
Refreshing data in a workbook in SharePoint Server
When you use a workbook in the browser, you are viewing data that is either native or external. Native data is stored directly in the workbook, and does not require an external data connection. External data is stored someplace else, such as on a server, and requires a connection to an external database.
Hope I was able to help you with this info.
NikolinoDE
I know I don't know anything (Socrates)
