how to monitor a UNC path to make sure a new file is added to the folder at 10am everyday.

I don't specifically have a ready made one, but if you make a DS that "AppliesTo" a system.hostname=="oneOfYourCollectors" (make sure it's in the same domain as the resource with the UNC path you want to check).  Then something like:

if ( test-path "\\servername\C$\Path\To\File.txt" ) { write-output "1" } else { write-output "0" }

as a powershell script should do the trick.