Hey bboy,
RDP requires a clear network path to your PC. That means you need to configure the software with the IP address of your PC, then you have to make sure the phone can connect to that IP address.
Configuration depends on where your phone is relative to your PC.
If your phone is on WIFI in the same network as your PC
Then all you should have to do is:
1) Configure Windows Firewall to allow port 3389 (default RDP port) or whatever port that product uses
2) Get your PC's IP address, and give it to the program on your phone.
2a) Hold the [Windows] key and press [R]
2b) Type "cmd" (without quotes) and press [Enter]
2c) Type "ipconfig" (without quotes) and press [Enter]
2d) Your IP address will be listed. It's probably 192.168.x.y, where x and y are some number
If your Phone is using 3G, or on a WIFI network other than the one your PC is on
In this case, you need to connect through the internet. This involves everything above, plus:
1) Look at the "ipconfig" data from the previous steps. Find the "Default Gateway" address
2) Enter that address into your browser on the PC
3) This will access the Router's configuration webpage
4) Make sure the firewall allows the proper port to enter
5) "Forward" the proper port to your PC's IP address
These are general steps. I'm not affiliated with that product, but I'm somewhat of an expert in that technology, so feel free to write back or PM me if you have more questions. All of this [often confusing] configuration was one of the reasons we wrote PhoneMyPC.
SoftwareForMe.com
Makers of PhoneMyPC