If you are worried about security, take a look at using VPN.
It is safer that remote connection.
Here are the steps for remote connection
1. On your router, go to either security or services depends on the model, forward port 3389 to the local list of IP addresses or (one server) / PCs that the remote users will connect to.
2. if you have a firewall like ISA, this will be secured as you will do the routing there.
3. Now give the user who needs to connect your outside IP address, it should be able to connect.