I actually got it working. I had to change the \\*\mailslots\LANegram\ to \\<computer name>\mailslots\LANegram\ and put the computer name into that section. As long as the computer name is passed, mailslots works across subnets that are on the same domain. Unfortunately, even passing an asterisk still is limited to the existing subnet, but since this work around gets across it, it has expanded the functionality of sending to a single computer, just not ALL computers which didn't work anyway across the subnet.
I have not done any testing on Win 8.x as we don't have any in our environment yet, but it works great with Win 7 machines.
Thanks for making a great little utility. I know it is old, but it still has functional uses in businesses.