How can I enable non-admin users to run a certain application (in my case, a script) with admin permissions on Windows XP?
This would be similar to the setuid bit on *nix.
Here is a previous very similar topic:
Short answer no, with a but. Long answer:
The proper Microsoft-approved way to do this is to create a "shim" for your application that redirects anything that needs admin rights to a similar user-mode area. For example, if your app tries to save a registry setting to HKLM, the shim will put it in HKCU instead.
Also check out the Aaron Margosis' blog for lots of detail on this type of thing.
There is a special program for these purposes - Admilink.
It creates an special encrypted link to targeted file (I test in only with .exe files) - you need to do this action only once. When you click on link - program (Admirun.exe) automatically starts the program in link with the special rights (Rigths depends of selected User during link creation process - you can use admin account or domain account name etc).
During link creating process (only once) you need to have admin account.
P.S. It's FREE for non-comercial use.
You can use Runas with a utility called SANUR.exe that allows the password to be piped in, instead having it typed!