If the Shell function successfully executes the named file, it returns the task ID of the started program. The task ID is a unique number that identifies the running program. If the Shell function can't start the named program, an error occurs.
On the Macintosh, vbNormalFocus, vbMinimizedFocus, and vbMaximizedFocus all place the application in the foreground; vbHide, vbNoFocus, vbMinimizeFocus all place the application in the background.
Note By default, the Shell function runs other programs asynchronously. This means that a program started with Shell might not finish executing before the statements following the Shell function are executed.
'so looks like you need to keep an eye on the progress of the ID that is started
'or you could cheat and use
Set WshShell = CreateObject("Wscript.Shell")
WshShell.Run "c:\notepad.exe", 1, True
where 1 is the window style and True is to wait for the thread to terminate..