Não é fácil. De The Old New Coisa :
VideoReDo 19 Jan 2007 4:20 PM
I'm running a 3 monitor system, all 1280 x 1024. If I /span to another machine the remote desktop occupies all 3 displays. What I really would like to do is have the /span work across 2 displays, leaving the 3rd monitor displaying windows from the host machine (email, IM, etc).
Was able to simulate this by disabling the 3rd monitor, starting mstsc /span, and then re-enabling the 3rd monitor. Works great, but its a pain to setup each time.
Does anyone know a way to have mstsc span a limited number of monitors? Using /w and /h work OK, but then I don't get the nice little title bar like you do with the /span.
All in all though, the /span is a significant improvment over previous releases.