InstallAware

I need UAC for my setup because I'm installing system components (VC redist). Therefor the setup needs admin rights.
But I am quite sure that the updateclient doesn't need these rights, so it would be nice if a call to setup.exe /update wouldn't show the UAC. Is this possible somehow?

I have separated the update script in an extra project and will now deploy this updater.exe with my application. Therefor I will just call the updater with the parameters for LANGUAGE and VERSION (and of curse /update). It seems to work.
Has anybody experience with this approach?