Unfortunatly the Windows API in this case are cumbersome.
However if I click on the node/folder of the TreeCtrl the new file is displayed. So a sort of sync is performed. I would like to try to simulate the close/open of the node where the file is. Unfortunately I do not understand how each node id map a given folder.
have you tried FindFile class of U++?
It can check timestamps (directory object change times).