I managed to control the SX200 remotelly via PC but I had to write a middleware to do it and to modify the CHDK PTP software to eliminate the use of many scripts and to cope with constant camera shutdown. But still I sometimes get a shutdown of the camera. If you are going to use it for yoursenf (no-commercial use) and you can stand the annoyance of the shutdowns the current software can do the job. Otherwise, you better do what I did.