This is Drive "F:\", the bug with weird symbols has been fixed for the upcoming v8 release.
With respect to overrides - you need to apply them to the group of virtual machines, because this monitor is targeted to a VM class. The correct group should be "VMware VMs that run Ops Mgr agents". Also feel free to use regular expression to remove certain disk drive from the monitoring scope, for example "F:\\.*" added to the ExcludeDisks parameter will remove "F:\ вЂ“" disk from the scope.
I'm terribly sorry for this issue with this weird symbols in the disk name, we've fixed this in the upcoming release and we hope it will be available soon.
Let me know if you have any other questions regarding this or any other Veeam MP monitors.