Logout Office 365 user from a PC

Hello Guys,

I'm looking for a remote way to logout a user from Excel, automated way preferably. I have a lot of computers where I have excel running I need to switch the user in all of them, so I'm looking for a powershell cmdlet, vbs or cmd command to do that. 

I know the manual process is to go to excel and at the top account listed and click "Sign out"; but I can't go PC by PC doing that. So I'm looking for a way to automate this. 

Things to take into consideration:

1. Logoff device from Office Portal option has been disabled in my organization.

2. I'm not a tenant administrator to do a mass logoff.

I'm actually looking for a way to create a script and do this remotely.

Thanks in advance!