Setting Security on Service Categories

We have a few different service categories at our site. We have a couple that only specific domain groups should have access to. Management for example. Is there a way to restrict access to these service categories based on AD group? I have already tried to set NTFS security on the .xml, however Altiris is using the service account on the back end to access the .xml, so that did not work. Any assistance would be appreciated. Thanks.