Okay.
I tested the app and I'd like to mention that sometimes (very rarely) it cuts the fragments incorrectly.
For example, the program may copy entire file instead of cutting desired fragment, or it can cut wrong fragment.
Also, when using DS filter in GraphEdit and specifying start and stop positions in filter's property page, the sound in the very end of resulting fragment (a number of seconds) may be absent.
I also tried to use the COM object in my app since its interface doesn't look very intricate
Sometimes it worked, but the most times it didn't.
I used the following sequence of calls of object's methods:
CreateInstance
put_InputFN
put_OutputFN
put_StartPosition
put_StopPosition
Start
I didn't track the object's behavior through processing its events.