I personally needed to add items from a network share to the local start menu, now all group policy's out there only add user specific start menu items and don't get stored in c:\programdata\microsoft\windows\start menu\programs\
our third party launch bar only looks at this directory so adding programs to the eduSTAR bar was impossible through group policy alone hence the need for an additional script and task.
using xcopy or robocopy threw errors and running the script as an admin would still give permission denied errors.
the answer for me was creating a scheduled task "on login" that runs any executable/script with admin privleges.
For me any customly installed programs are removed from the start menu each day using the following code, this isn't needed unless you want to forcefully remove all start menu items:
robocopy c:\programdata\microsoft\windows\start menu\programs c:\temp /e /MOVE /MINAGE:1
rmdir c:\temp /s /q
The next part of the code copies from the server share location with the shortcuts to the local windows start menu location.
robocopy "\\server\netlogon\StartMenuShortcuts" "C:\programdata\microsoft\windows\start menu\programs" /is /e
Now with all your shortcuts within the server share's folder "StartMenuShortcuts" can be named anything i just named it this for ease of reading, each time someone logs in it will remove all the shortcuts currently in the start menu and replace them with the shortcuts in the "StartMenuShortcuts" folder, allowing you to enforce and add/remove anything you want, the /is parameter won't copy if its already in the location, due to all shortcuts being extremely small this has little to no impact on login performance.
I've also used this method to run vbs scripts that call msi files that require elivated privleges, Scheduled tasks are much more powerful when accompanied with login scripts as it runs before the user see's their desktop (handy if you want to hide your login scripts cmd window)
anyways hope this helps, I wish i worked this out years ago, would of saved me weeks of work.