CreateProcessAsUser on Terminal Server

I created a service that is launching processes as Administrator user. There
is an application that talks to service and passes all information about
application needed for a launch. Service knows what applications it can
launch just to make sure operator cannot launch just about anything it wants
(but only some applications). This all works OK until I tried this on
Terminal Server. Behavior is that launched applications are always running
on the Terminal Server interactive desktop. Does anyone know how to force
process into other login session or how to make sure this process ends up
inside terminal client window.

I used most of the code in MSDN article:
Platform SDK: Security Starting an Interactive Client Process

Thanks in advance.