About Software Rights in W2K

Hi,
I have Windows 2000 Advanced Server with active directory installed.I created 5 OU’s on it.I have some applications installed on my W2K Server but i want to restrict my users to use some spcific applications.For Ex. Sales OU can use Ms-Office,Marketing OU can use Oracle etc.How i give permission to all the OU’s to use some spcific applications.
Regards.
Anurag.