Oh Nostalgia. Way, way before the explosion of RD (remote desktop) I wrote client/server application that mimics at the very minimal functionality of what is known today RD.
Well, there is good news and bad news for you. What you need to to intercept keyboard keystrokes and then *send* it to the other end of the wire. In most cases this should work straight off the bat including WINDOWS KEY combinations. But that won't help you with Ctrl+Alt+Delete key sequence as it is handled separately and differently from the rest of the keyboard messages. It does even exist in the messages if you want to listen to it.
In the old days (Pre Vista) it was handled by GINA
], I think after Vista it is slightly different. If you want to handle it then you will need to write GINA replacement. But, unless there is compelling reason please don't do it. spare your self the agony.
As Marcus suggested there are plenty good RD out there. Make use of them. Personally, I use DameWare mini Remote Control
]. It simply is an amazing tool. By the way, it will do what you need.