OK, this isn't pretty, but it works if you absolutely have to wake up a
remote machine and you can't enable Directed Subnet Broadcast on your
router(s).

First, make sure the WOL Service is enabled on a server at the remote site.

Second, in the Server policy package at the remote site create a Wake On
LAN policy. I have a policy that wakes up certain machines every
morning, so for this purpose I create a second policy.

Add the workstation to be wakened to the policy.

Set the policy schedule (not the Package schedule) to Daily, and repeat
every minute or so.

Apply the changes to the policy, make sure "Enabled" is checked, then
apply the changes to the policy package.

Remote to the server console and at the console prompt type "STOPWOL".
When control returns to the console type "STARTWOL."

On the ZENworks Wake on LAN screen watch for "Packet sent to remote
machine. At that point you can disable the WOL policy in the server
package and apply the change.

At the server console prompt type "STOPWOL". When control returns to the
console type "STARTWOL."

As I said, it isn't pretty, but it works.

It would be nice to have an enhancement to the WOL service that allows
command-line immediate wakeups.