Add an application to an Application Control Policy

Hi

I need to add an application to an Application Control Policy, for example PSExec.exe (part of PSTools).

Currently I've added it (by path) to Global Settings > Allowed Applications, but this will 'allow' it on any machine/user.  I have created a separate Application Control policy that is assigned to an IT Group which is less strict than the base policy.  I'd like to add this application to that policy, so that it is cleaned on non-IT machines but allowed on IT Machines.  How would I go about this?

Thanks
Tony