The SLR camera is mostly connected via the USB port with the computer.
A remote control of zoom, screen and focus by software on the computer is possible if a public interface is available.
qStopMotion use the gphoto2 standard interface to control SLR cameras on the Linux platform. A list of the supported cameras can you find on the project projekt web site.
There is no public standard interface to control SLR cameras on the Windows platform. Each manufacturer has it's own programming interface or nothing. For the gphoto2 library exists no port to Windows for the Microsoft compiler.