Gateway RAP Network Resource Policy and AD groups

I have been having difficulties getting the computer permissions to work by group in the RA Network Resource policy for remote desktop farms in HA mode.  Published app's fail to connect because I cannot find a way to add the HA gateway name to an AD group.  The AD group needs a computer account with the alias name of the connection broker.

I am always forced to use a RD Gateway-managed group or allow users to connect to any network resource in the RA policy.  Either of these are not desirable, we'd like to use a single AD group for this across multiple RDS servers in our farm.

Does anyone know a simple way to add an AD alias "computer" account for the HA Gateway name so I add it to an AD group and use that group in the RA Gateway policy to allow users to connect to published apps on the RDS servers themselves?