IP Port security

We have a Cisco Firewall with VPN capability, yet my boss’s computer has a problem with the Cisco VPN client software. Accessing the VPN is not critical, yet he does want to be able to access our CRM application (Goldmine). Is there a way to setup Terminal Services as an application server and access it securely without a VPN connection? With Goldmine, you can also set up a remote site and synchronize with the main database remotely using IP port 5993. What is the best way to allow secure access via port 5993?