Combining two or more applications in one is just a job, not a technical question. If you do not have appropriate development skills to learn how applications work using their source code and documentation and to implement combined functionality, no quick answer can ever help you.
If you have such skills but are hoping that someone will volunteer to do this or part of this job for you, you are probably too naive.
So, either way, the question was pretty much pointless.
But I hope you already got what would be my final answer to your question. That is: get to work!
By the way, if you do the job and face particular problems you can clearly describe, we will gladly try to help you.
[EDIT]
In reply to OP's comments:
You also don't explain in detail what do you want to achieve, more exactly. First of all, do you want to use existing RDP protocol or not?
(Please see
http://en.wikipedia.org/wiki/Remote_Desktop_Protocol[
^]).
If not, you would need to create your own and create a Windows Service to support it, run it on each target system. I don't know if you need help with Windows Services or not.
In both cases, you might want to create just client part or client and server as well. Why not using existing RDP clients? If you want to create your own, it should be motivated somehow. Maybe you need to offer additional or better features. What kind of features?
You see, you cannot get help if you just say "I want…" You have to be more specific. Do you see the point?
By the way, you may want to check these CodeProject articles:
http://www.codeproject.com/KB/cs/RemoteDesktop_CSharpNET.aspx[
^],
Palantir - Remote Desktop Manager[
^].
Palanir is my favorite, by the way.
—SA