Sharing PC using TS

Hi,

Is it possible using Terminale Server (TS) so that the person from the outside and I share the same screen.
Someone from the outside needs to conect him to a server, but we want to work together on te same screen, I will be working locally and he will conect himself to the server using TS. But I always thought that TS is a session, so what he does, you will not see (mocing mouse, opening Tables,etc...)
Using a comercial program like Nesupport I believe it is possible, or even VNC. But can it be done with TS?

Many thx!