How to merge two streams

Hi All, Please see my requirements and do let me know if it is possible using evo medial server. 1) We will setup a webcam and that will capture video and audio and it will to send to evo media server. 2) And from another PC (designation stream) stream an audio signal into the server. In other words the "designation" PC is sourcing an audio but pulling in a Video stream onto a player. The recording must be a combination of video + audio from the source and the audio from a second stream. Can you let us know if such things can be done using evostream server and if yes how we can achieve it?